diff --git a/src/Base.zig b/src/Base.zig
index 9928819..0f9714b 100644
--- a/src/Base.zig
+++ b/src/Base.zig
@@ -5,22 +5,32 @@ const Dimensions = @import("Dimensions.zig");
 const Scales = @import("Scales.zig");
 const Scalar = @import("Scalar.zig").Scalar;
 
-/// Helper function to create a clean namespace for each physical dimension.
-/// It exposes the raw dimensions, and easy type-creators for Base or Scaled variants.
-pub fn BaseScalar(comptime d: anytype) type {
+fn PhysicalConstant(comptime d: Dimensions.ArgOpts, comptime val: f64, comptime s: Scales.ArgOpts) type {
     return struct {
-        pub const dims = Dimensions.init(d);
+        const dims = Dimensions.init(d);
+        const scales = Scales.init(s);
+
+        /// Instantiates the constant into a specific numeric type.
+        pub fn Of(comptime T: type) Scalar(T, d, s) {
+            return .{ .value = @as(T, @floatCast(val)) };
+        }
+    };
+}
+
+fn BaseScalar(comptime d: Dimensions.ArgOpts) type {
+    return struct {
+        const dims = Dimensions.init(d);
 
         /// Creates a Scalar of this dimension using default scales.
         /// Example: const V = Quantities.Velocity.Base(f32);
         pub fn Of(comptime T: type) type {
-            return Scalar(T, dims, Scales.init(.{}));
+            return Scalar(T, d, .{});
         }
 
         /// Creates a Scalar of this dimension using custom scales.
         /// Example: const Kmh = Quantities.Velocity.Scaled(f32, Scales.init(.{ .L = .k, .T = .hour }));
-        pub fn Scaled(comptime T: type, comptime s: Scales) type {
-            return Scalar(T, dims, s);
+        pub fn Scaled(comptime T: type, comptime s: Scales.ArgOpts) type {
+            return Scalar(T, d, s);
         }
     };
 }
@@ -95,6 +105,31 @@ pub const Frequency = BaseScalar(.{ .T = -1 });
 pub const Viscosity = BaseScalar(.{ .M = 1, .L = -1, .T = -1 });
 pub const SurfaceTension = BaseScalar(.{ .M = 1, .T = -2 }); // Corrected from MT-2a
 
+// ==========================================
+// Physical Constants
+// ==========================================
+pub const Constants = struct {
+    /// Speed of light in vacuum
+    pub const c = Speed.Constant(299792458.0, Scales.init(.{}));
+
+    /// Standard gravity
+    pub const g = Acceleration.Constant(9.80665, Scales.init(.{}));
+
+    /// Newton's Gravitational Constant: L³ M⁻¹ T⁻²
+    pub const GravitationalConstant = PhysicalConstant(
+        .{ .L = 3, .M = -1, .T = -2 },
+        6.67430e-11,
+        Scales.init(.{}),
+    );
+
+    /// Planck Constant: M L² T⁻¹
+    pub const Planck = PhysicalConstant(
+        .{ .M = 1, .L = 2, .T = -1 },
+        6.62607015e-34,
+        Scales.init(.{}),
+    );
+};
+
 test "BaseQuantities - Core dimensions instantiation" {
     // Basic types via generic wrappers
     const M = Meter.Of(f32);
@@ -104,7 +139,7 @@ test "BaseQuantities - Core dimensions instantiation" {
     try std.testing.expectEqual(0, M.dims.get(.T));
 
     // Test specific scale variants
-    const Kmh = Speed.Scaled(f32, Scales.init(.{ .L = .k, .T = .hour }));
+    const Kmh = Speed.Scaled(f32, .{ .L = .k, .T = .hour });
     const speed = Kmh{ .value = 120.0 };
     try std.testing.expectEqual(120.0, speed.value);
     try std.testing.expectEqual(.k, @TypeOf(speed).scales.get(.L));
@@ -128,7 +163,7 @@ test "BaseQuantities - Kinematics equations" {
 
 test "BaseQuantities - Dynamics (Force and Work)" {
     // 10 kg
-    const m = Gramm.Scaled(f32, Scales.init(.{ .M = .k })){ .value = 10.0 };
+    const m = Gramm.Scaled(f32, .{ .M = .k }){ .value = 10.0 };
     // 9.8 m/s^2
     const a = Acceleration.Of(f32){ .value = 9.8 };
 
diff --git a/src/Dimensions.zig b/src/Dimensions.zig
index 92e3531..3953fe0 100644
--- a/src/Dimensions.zig
+++ b/src/Dimensions.zig
@@ -1,5 +1,15 @@
 const std = @import("std");
 
+pub const ArgOpts = struct {
+    L: comptime_int = 0,
+    M: comptime_int = 0,
+    T: comptime_int = 0,
+    I: comptime_int = 0,
+    Tp: comptime_int = 0,
+    N: comptime_int = 0,
+    J: comptime_int = 0,
+};
+
 pub const Dimension = enum {
     /// Length
     L,
@@ -37,9 +47,9 @@ const Self = @This();
 
 data: std.EnumArray(Dimension, comptime_int),
 
-/// Create a `Dimensions` from an anonymous struct literal, e.g. `.{ .L = 1, .T = -1 }`.
+/// Create a `Dimensions` from a struct literal, e.g. `.{ .L = 1, .T = -1 }`.
 /// Unspecified dimensions default to 0.
-pub fn init(comptime init_val: anytype) Self {
+pub fn init(comptime init_val: ArgOpts) Self {
     var s = Self{ .data = std.EnumArray(Dimension, comptime_int).initFill(0) };
     inline for (std.meta.fields(@TypeOf(init_val))) |f|
         s.data.set(@field(Dimension, f.name), @field(init_val, f.name));
diff --git a/src/Scalar.zig b/src/Scalar.zig
index 55564fb..60b6965 100644
--- a/src/Scalar.zig
+++ b/src/Scalar.zig
@@ -7,12 +7,17 @@ const UnitScale = Scales.UnitScale;
 const Dimensions = @import("Dimensions.zig");
 const Dimension = Dimensions.Dimension;
 
-// TODO: Be able to use comptime float and int and T for mulBy ect
-// Which endup being Dimension less
+// TODO:
+//  - Be able to use comptime float and int and T for mulBy ect
+//  Which endup being Dimension less
 
 /// A dimensioned scalar value. `T` is the numeric type, `d` the dimension exponents, `s` the SI scales.
 /// All dimension and unit tracking is resolved at comptime — zero runtime overhead.
-pub fn Scalar(comptime T: type, comptime d: Dimensions, comptime s: Scales) type {
+pub fn Scalar(comptime T: type, comptime d_opt: Dimensions.ArgOpts, comptime s_opt: Scales.ArgOpts) type {
+    return Scalar_(T, Dimensions.init(d_opt), Scales.init(s_opt));
+}
+
+pub fn Scalar_(comptime T: type, comptime d: Dimensions, comptime s: Scales) type {
     @setEvalBranchQuota(10_000_000);
     return struct {
         value: T,
@@ -33,7 +38,7 @@ pub fn Scalar(comptime T: type, comptime d: Dimensions, comptime s: Scales) type
 
         /// Add two quantities. Dimensions must match — compile error otherwise.
         /// Scales are auto-resolved to the finer of the two.
-        pub inline fn add(self: Self, rhs: anytype) Scalar(
+        pub inline fn add(self: Self, rhs: anytype) Scalar_(
             T,
             dims,
             hlp.finerScales(Self, @TypeOf(rhs)),
@@ -43,7 +48,7 @@ pub fn Scalar(comptime T: type, comptime d: Dimensions, comptime s: Scales) type
             if (comptime @TypeOf(rhs) == Self)
                 return .{ .value = self.value + rhs.value };
 
-            const TargetType = Scalar(T, dims, hlp.finerScales(Self, @TypeOf(rhs)));
+            const TargetType = Scalar_(T, dims, hlp.finerScales(Self, @TypeOf(rhs)));
             const lhs_val = if (comptime @TypeOf(self) == TargetType) self.value else self.to(TargetType).value;
             const rhs_val = if (comptime @TypeOf(rhs) == TargetType) rhs.value else rhs.to(TargetType).value;
 
@@ -52,7 +57,7 @@ pub fn Scalar(comptime T: type, comptime d: Dimensions, comptime s: Scales) type
 
         /// Subtract two quantities. Dimensions must match — compile error otherwise.
         /// Scales are auto-resolved to the finer of the two.
-        pub inline fn sub(self: Self, rhs: anytype) Scalar(
+        pub inline fn sub(self: Self, rhs: anytype) Scalar_(
             T,
             dims,
             hlp.finerScales(Self, @TypeOf(rhs)),
@@ -62,7 +67,7 @@ pub fn Scalar(comptime T: type, comptime d: Dimensions, comptime s: Scales) type
             if (comptime @TypeOf(rhs) == Self)
                 return .{ .value = self.value - rhs.value };
 
-            const TargetType = Scalar(T, dims, hlp.finerScales(Self, @TypeOf(rhs)));
+            const TargetType = Scalar_(T, dims, hlp.finerScales(Self, @TypeOf(rhs)));
             const lhs_val = if (comptime @TypeOf(self) == TargetType) self.value else self.to(TargetType).value;
             const rhs_val = if (comptime @TypeOf(rhs) == TargetType) rhs.value else rhs.to(TargetType).value;
 
@@ -70,14 +75,14 @@ pub fn Scalar(comptime T: type, comptime d: Dimensions, comptime s: Scales) type
         }
 
         /// Multiply two quantities. Dimension exponents are summed: `L¹ * T⁻¹ → L¹T⁻¹`.
-        pub inline fn mulBy(self: Self, rhs: anytype) Scalar(
+        pub inline fn mulBy(self: Self, rhs: anytype) Scalar_(
             T,
             dims.add(@TypeOf(rhs).dims),
             hlp.finerScales(Self, @TypeOf(rhs)),
         ) {
             const RhsType = @TypeOf(rhs);
-            const SelfNorm = Scalar(T, dims, hlp.finerScales(Self, @TypeOf(rhs)));
-            const RhsNorm = Scalar(T, RhsType.dims, hlp.finerScales(Self, @TypeOf(rhs)));
+            const SelfNorm = Scalar_(T, dims, hlp.finerScales(Self, @TypeOf(rhs)));
+            const RhsNorm = Scalar_(T, RhsType.dims, hlp.finerScales(Self, @TypeOf(rhs)));
             if (comptime Self == SelfNorm and RhsType == RhsNorm)
                 return .{ .value = self.value * rhs.value };
 
@@ -88,14 +93,14 @@ pub fn Scalar(comptime T: type, comptime d: Dimensions, comptime s: Scales) type
 
         /// Divide two quantities. Dimension exponents are subtracted: `L¹ / T¹ → L¹T⁻¹`.
         /// Integer types use truncating division.
-        pub inline fn divBy(self: Self, rhs: anytype) Scalar(
+        pub inline fn divBy(self: Self, rhs: anytype) Scalar_(
             T,
             dims.sub(@TypeOf(rhs).dims),
             hlp.finerScales(Self, @TypeOf(rhs)),
         ) {
             const RhsType = @TypeOf(rhs);
-            const SelfNorm = Scalar(T, dims, hlp.finerScales(Self, @TypeOf(rhs)));
-            const RhsNorm = Scalar(T, RhsType.dims, hlp.finerScales(Self, @TypeOf(rhs)));
+            const SelfNorm = Scalar_(T, dims, hlp.finerScales(Self, @TypeOf(rhs)));
+            const RhsNorm = Scalar_(T, RhsType.dims, hlp.finerScales(Self, @TypeOf(rhs)));
             const lhs_val = if (comptime Self == SelfNorm) self.value else self.to(SelfNorm).value;
             const rhs_val = if (comptime RhsType == RhsNorm) rhs.value else rhs.to(RhsNorm).value;
             if (comptime @typeInfo(T) == .int) {
@@ -116,7 +121,7 @@ pub fn Scalar(comptime T: type, comptime d: Dimensions, comptime s: Scales) type
 
         /// Raises the quantity to a compile-time integer exponent.
         /// Dimension exponents are multiplied by the exponent: `(L²)³ → L⁶`.
-        pub inline fn pow(self: Self, comptime exp: comptime_int) Scalar(
+        pub inline fn pow(self: Self, comptime exp: comptime_int) Scalar_(
             T,
             dims.scale(exp),
             s,
@@ -127,7 +132,7 @@ pub fn Scalar(comptime T: type, comptime d: Dimensions, comptime s: Scales) type
                 return .{ .value = std.math.pow(T, self.value, @as(T, @floatFromInt(exp))) };
         }
 
-        pub inline fn sqrt(self: Self) Scalar(
+        pub inline fn sqrt(self: Self) Scalar_(
             T,
             dims.div(2),
             s,
@@ -196,7 +201,7 @@ pub fn Scalar(comptime T: type, comptime d: Dimensions, comptime s: Scales) type
             if (comptime @TypeOf(rhs) == Self)
                 return self.value == rhs.value;
 
-            const TargetType = Scalar(T, dims, hlp.finerScales(Self, @TypeOf(rhs)));
+            const TargetType = Scalar_(T, dims, hlp.finerScales(Self, @TypeOf(rhs)));
             const lhs_val = if (comptime @TypeOf(self) == TargetType) self.value else self.to(TargetType).value;
             const rhs_val = if (comptime @TypeOf(rhs) == TargetType) rhs.value else rhs.to(TargetType).value;
 
@@ -211,7 +216,7 @@ pub fn Scalar(comptime T: type, comptime d: Dimensions, comptime s: Scales) type
             if (comptime @TypeOf(rhs) == Self)
                 return self.value != rhs.value;
 
-            const TargetType = Scalar(T, dims, hlp.finerScales(Self, @TypeOf(rhs)));
+            const TargetType = Scalar_(T, dims, hlp.finerScales(Self, @TypeOf(rhs)));
             const lhs_val = if (comptime @TypeOf(self) == TargetType) self.value else self.to(TargetType).value;
             const rhs_val = if (comptime @TypeOf(rhs) == TargetType) rhs.value else rhs.to(TargetType).value;
 
@@ -226,7 +231,7 @@ pub fn Scalar(comptime T: type, comptime d: Dimensions, comptime s: Scales) type
             if (comptime @TypeOf(rhs) == Self)
                 return self.value > rhs.value;
 
-            const TargetType = Scalar(T, dims, hlp.finerScales(Self, @TypeOf(rhs)));
+            const TargetType = Scalar_(T, dims, hlp.finerScales(Self, @TypeOf(rhs)));
             const lhs_val = if (comptime @TypeOf(self) == TargetType) self.value else self.to(TargetType).value;
             const rhs_val = if (comptime @TypeOf(rhs) == TargetType) rhs.value else rhs.to(TargetType).value;
 
@@ -240,7 +245,7 @@ pub fn Scalar(comptime T: type, comptime d: Dimensions, comptime s: Scales) type
             if (comptime @TypeOf(rhs) == Self)
                 return self.value >= rhs.value;
 
-            const TargetType = Scalar(T, dims, hlp.finerScales(Self, @TypeOf(rhs)));
+            const TargetType = Scalar_(T, dims, hlp.finerScales(Self, @TypeOf(rhs)));
             const lhs_val = if (comptime @TypeOf(self) == TargetType) self.value else self.to(TargetType).value;
             const rhs_val = if (comptime @TypeOf(rhs) == TargetType) rhs.value else rhs.to(TargetType).value;
 
@@ -255,7 +260,7 @@ pub fn Scalar(comptime T: type, comptime d: Dimensions, comptime s: Scales) type
             if (comptime @TypeOf(rhs) == Self)
                 return self.value < rhs.value;
 
-            const TargetType = Scalar(T, dims, hlp.finerScales(Self, @TypeOf(rhs)));
+            const TargetType = Scalar_(T, dims, hlp.finerScales(Self, @TypeOf(rhs)));
             const lhs_val = if (comptime @TypeOf(self) == TargetType) self.value else self.to(TargetType).value;
             const rhs_val = if (comptime @TypeOf(rhs) == TargetType) rhs.value else rhs.to(TargetType).value;
 
@@ -269,7 +274,7 @@ pub fn Scalar(comptime T: type, comptime d: Dimensions, comptime s: Scales) type
             if (comptime @TypeOf(rhs) == Self)
                 return self.value <= rhs.value;
 
-            const TargetType = Scalar(T, dims, hlp.finerScales(Self, @TypeOf(rhs)));
+            const TargetType = Scalar_(T, dims, hlp.finerScales(Self, @TypeOf(rhs)));
             const lhs_val = if (comptime @TypeOf(self) == TargetType) self.value else self.to(TargetType).value;
             const rhs_val = if (comptime @TypeOf(rhs) == TargetType) rhs.value else rhs.to(TargetType).value;
 
@@ -329,8 +334,8 @@ pub fn Scalar(comptime T: type, comptime d: Dimensions, comptime s: Scales) type
 }
 
 test "Generate quantity" {
-    const Meter = Scalar(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = -3 }));
-    const Second = Scalar(f32, Dimensions.init(.{ .T = 1 }), Scales.init(.{ .T = .n }));
+    const Meter = Scalar(i128, .{ .L = 1 }, .{ .L = @enumFromInt(-3) });
+    const Second = Scalar(f32, .{ .T = 1 }, .{ .T = .n });
 
     const distance = Meter{ .value = 10 };
     const time = Second{ .value = 2 };
@@ -340,8 +345,8 @@ test "Generate quantity" {
 }
 
 test "Comparisons (eq, ne, gt, gte, lt, lte)" {
-    const Meter = Scalar(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
-    const KiloMeter = Scalar(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = .k }));
+    const Meter = Scalar(i128, .{ .L = 1 }, .{});
+    const KiloMeter = Scalar(i128, .{ .L = 1 }, .{ .L = .k });
 
     const m1000 = Meter{ .value = 1000 };
     const km1 = KiloMeter{ .value = 1 };
@@ -366,7 +371,7 @@ test "Comparisons (eq, ne, gt, gte, lt, lte)" {
 }
 
 test "Add" {
-    const Meter = Scalar(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
+    const Meter = Scalar(i128, .{ .L = 1 }, .{});
 
     const distance = Meter{ .value = 10 };
     const distance2 = Meter{ .value = 20 };
@@ -375,7 +380,7 @@ test "Add" {
     try std.testing.expectEqual(30, added.value);
     try std.testing.expectEqual(1, @TypeOf(added).dims.get(.L));
 
-    const KiloMeter = Scalar(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = .k }));
+    const KiloMeter = Scalar(i128, .{ .L = 1 }, .{ .L = .k });
     const distance3 = KiloMeter{ .value = 2 };
     const added2 = distance.add(distance3);
     try std.testing.expectEqual(2010, added2.value);
@@ -385,7 +390,7 @@ test "Add" {
     try std.testing.expectEqual(2, added3.value);
     try std.testing.expectEqual(1, @TypeOf(added3).dims.get(.L));
 
-    const KiloMeter_f = Scalar(f64, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = .k }));
+    const KiloMeter_f = Scalar(f64, .{ .L = 1 }, .{ .L = .k });
     const distance4 = KiloMeter_f{ .value = 2 };
     const added4 = distance4.add(distance).to(KiloMeter_f);
     try std.testing.expectApproxEqAbs(2.01, added4.value, 0.000001);
@@ -393,8 +398,8 @@ test "Add" {
 }
 
 test "Sub" {
-    const Meter = Scalar(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
-    const KiloMeter_f = Scalar(f64, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = .k }));
+    const Meter = Scalar(i128, .{ .L = 1 }, .{});
+    const KiloMeter_f = Scalar(f64, .{ .L = 1 }, .{ .L = .k });
 
     const a = Meter{ .value = 500 };
     const b = Meter{ .value = 200 };
@@ -410,8 +415,8 @@ test "Sub" {
 }
 
 test "MulBy" {
-    const Meter = Scalar(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
-    const Second = Scalar(f32, Dimensions.init(.{ .T = 1 }), Scales.init(.{}));
+    const Meter = Scalar(i128, .{ .L = 1 }, .{});
+    const Second = Scalar(f32, .{ .T = 1 }, .{});
 
     const d = Meter{ .value = 3.0 };
     const t = Second{ .value = 4.0 };
@@ -429,8 +434,8 @@ test "MulBy" {
 }
 
 test "MulBy with scale" {
-    const KiloMeter = Scalar(f32, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = .k }));
-    const KiloGram = Scalar(f32, Dimensions.init(.{ .M = 1 }), Scales.init(.{ .M = .k }));
+    const KiloMeter = Scalar(f32, .{ .L = 1 }, .{ .L = .k });
+    const KiloGram = Scalar(f32, .{ .M = 1 }, .{ .M = .k });
 
     const dist = KiloMeter{ .value = 2.0 };
     const mass = KiloGram{ .value = 3.0 };
@@ -440,10 +445,10 @@ test "MulBy with scale" {
 }
 
 test "MulBy with type change" {
-    const Meter = Scalar(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = .k }));
-    const Second = Scalar(f64, Dimensions.init(.{ .T = 1 }), Scales.init(.{}));
-    const KmSec = Scalar(i64, Dimensions.init(.{ .L = 1, .T = 1 }), Scales.init(.{ .L = .k }));
-    const KmSec_f = Scalar(f32, Dimensions.init(.{ .L = 1, .T = 1 }), Scales.init(.{ .L = .k }));
+    const Meter = Scalar(i128, .{ .L = 1 }, .{ .L = .k });
+    const Second = Scalar(f64, .{ .T = 1 }, .{});
+    const KmSec = Scalar(i64, .{ .L = 1, .T = 1 }, .{ .L = .k });
+    const KmSec_f = Scalar(f32, .{ .L = 1, .T = 1 }, .{ .L = .k });
 
     const d = Meter{ .value = 3.0 };
     const t = Second{ .value = 4.0 };
@@ -457,8 +462,8 @@ test "MulBy with type change" {
 }
 
 test "MulBy small" {
-    const Meter = Scalar(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = .n }));
-    const Second = Scalar(f32, Dimensions.init(.{ .T = 1 }), Scales.init(.{}));
+    const Meter = Scalar(i128, .{ .L = 1 }, .{ .L = .n });
+    const Second = Scalar(f32, .{ .T = 1 }, .{});
 
     const d = Meter{ .value = 3.0 };
     const t = Second{ .value = 4.0 };
@@ -470,8 +475,8 @@ test "MulBy small" {
 }
 
 test "MulBy dimensionless" {
-    const DimLess = Scalar(i128, Dimensions.init(.{}), Scales.init(.{}));
-    const Meter = Scalar(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
+    const DimLess = Scalar(i128, .{}, .{});
+    const Meter = Scalar(i128, .{ .L = 1 }, .{});
 
     const d = Meter{ .value = 7 };
     const scaled = d.mulBy(DimLess{ .value = 3 });
@@ -480,7 +485,7 @@ test "MulBy dimensionless" {
 }
 
 test "Sqrt" {
-    const MeterSquare = Scalar(i128, Dimensions.init(.{ .L = 2 }), Scales.init(.{}));
+    const MeterSquare = Scalar(i128, .{ .L = 2 }, .{});
 
     var d = MeterSquare{ .value = 9 };
     var scaled = d.sqrt();
@@ -492,7 +497,7 @@ test "Sqrt" {
     try std.testing.expectEqual(0, scaled.value);
     try std.testing.expectEqual(1, @TypeOf(scaled).dims.get(.L));
 
-    const MeterSquare_f = Scalar(f64, Dimensions.init(.{ .L = 2 }), Scales.init(.{}));
+    const MeterSquare_f = Scalar(f64, .{ .L = 2 }, .{});
     const d2 = MeterSquare_f{ .value = 20 };
     const scaled2 = d2.sqrt();
     try std.testing.expectApproxEqAbs(4.472135955, scaled2.value, 1e-4);
@@ -500,8 +505,8 @@ test "Sqrt" {
 }
 
 test "Chained: velocity and acceleration" {
-    const Meter = Scalar(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
-    const Second = Scalar(f32, Dimensions.init(.{ .T = 1 }), Scales.init(.{}));
+    const Meter = Scalar(i128, .{ .L = 1 }, .{});
+    const Second = Scalar(f32, .{ .T = 1 }, .{});
 
     const dist = Meter{ .value = 100.0 };
     const t1 = Second{ .value = 5.0 };
@@ -518,8 +523,8 @@ test "Chained: velocity and acceleration" {
 }
 
 test "DivBy integer exact" {
-    const Meter = Scalar(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
-    const Second = Scalar(f32, Dimensions.init(.{ .T = 1 }), Scales.init(.{}));
+    const Meter = Scalar(i128, .{ .L = 1 }, .{});
+    const Second = Scalar(f32, .{ .T = 1 }, .{});
 
     const dist = Meter{ .value = 120 };
     const time = Second{ .value = 4 };
@@ -531,8 +536,8 @@ test "DivBy integer exact" {
 }
 
 test "Finer scales skip dim 0" {
-    const Dimless = Scalar(i128, Dimensions.init(.{}), Scales.init(.{}));
-    const KiloMetre = Scalar(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = .k }));
+    const Dimless = Scalar(i128, .{}, .{});
+    const KiloMetre = Scalar(i128, .{ .L = 1 }, .{ .L = .k });
 
     const r = Dimless{ .value = 30 };
     const time = KiloMetre{ .value = 4 };
@@ -543,9 +548,9 @@ test "Finer scales skip dim 0" {
 }
 
 test "Conversion chain: km -> m -> cm" {
-    const KiloMeter = Scalar(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = .k }));
-    const Meter = Scalar(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
-    const CentiMeter = Scalar(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = .c }));
+    const KiloMeter = Scalar(i128, .{ .L = 1 }, .{ .L = .k });
+    const Meter = Scalar(i128, .{ .L = 1 }, .{});
+    const CentiMeter = Scalar(i128, .{ .L = 1 }, .{ .L = .c });
 
     const km = KiloMeter{ .value = 15 };
     const m = km.to(Meter);
@@ -556,9 +561,9 @@ test "Conversion chain: km -> m -> cm" {
 }
 
 test "Conversion: hours -> minutes -> seconds" {
-    const Hour = Scalar(i128, Dimensions.init(.{ .T = 1 }), Scales.init(.{ .T = .hour }));
-    const Minute = Scalar(i128, Dimensions.init(.{ .T = 1 }), Scales.init(.{ .T = .min }));
-    const Second = Scalar(i128, Dimensions.init(.{ .T = 1 }), Scales.init(.{}));
+    const Hour = Scalar(i128, .{ .T = 1 }, .{ .T = .hour });
+    const Minute = Scalar(i128, .{ .T = 1 }, .{ .T = .min });
+    const Second = Scalar(i128, .{ .T = 1 }, .{});
 
     const h = Hour{ .value = 1.0 };
     const min = h.to(Minute);
@@ -569,7 +574,7 @@ test "Conversion: hours -> minutes -> seconds" {
 }
 
 test "Negative values" {
-    const Meter = Scalar(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
+    const Meter = Scalar(i128, .{ .L = 1 }, .{});
 
     const a = Meter{ .value = 5 };
     const b = Meter{ .value = 20 };
@@ -578,17 +583,9 @@ test "Negative values" {
 }
 
 test "Format Scalar" {
-    const MeterPerSecondSq = Scalar(
-        f32,
-        Dimensions.init(.{ .L = 1, .T = -2 }),
-        Scales.init(.{ .T = .n }),
-    );
-    const KgMeterPerSecond = Scalar(
-        f32,
-        Dimensions.init(.{ .M = 1, .L = 1, .T = -1 }),
-        Scales.init(.{ .M = .k }),
-    );
-    const Meter = Scalar(f32, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
+    const MeterPerSecondSq = Scalar(f32, .{ .L = 1, .T = -2 }, .{ .T = .n });
+    const KgMeterPerSecond = Scalar(f32, .{ .M = 1, .L = 1, .T = -1 }, .{ .M = .k });
+    const Meter = Scalar(f32, .{ .L = 1 }, .{});
 
     const m = Meter{ .value = 1.23456 };
     const accel = MeterPerSecondSq{ .value = 9.81 };
@@ -609,20 +606,20 @@ test "Format Scalar" {
 }
 
 test "Abs" {
-    const Meter = Scalar(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
+    const Meter = Scalar(i128, .{ .L = 1 }, .{});
     const m1 = Meter{ .value = -50 };
     const m2 = m1.abs();
 
     try std.testing.expectEqual(50, m2.value);
     try std.testing.expectEqual(1, @TypeOf(m2).dims.get(.L));
 
-    const m_float = Scalar(f32, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
+    const m_float = Scalar(f32, .{ .L = 1 }, .{});
     const m3 = m_float{ .value = -42.5 };
     try std.testing.expectEqual(42.5, m3.abs().value);
 }
 
 test "Pow" {
-    const Meter = Scalar(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
+    const Meter = Scalar(i128, .{ .L = 1 }, .{});
     const d = Meter{ .value = 4 };
 
     const area = d.pow(2);
@@ -634,7 +631,7 @@ test "Pow" {
     try std.testing.expectEqual(3, @TypeOf(volume).dims.get(.L));
 
     // Float test
-    const MeterF = Scalar(f32, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
+    const MeterF = Scalar(f32, .{ .L = 1 }, .{});
     const d_f = MeterF{ .value = 2.0 };
     const area_f = d_f.pow(3);
     try std.testing.expectEqual(8.0, area_f.value);
diff --git a/src/Scales.zig b/src/Scales.zig
index e80ae79..f300e28 100644
--- a/src/Scales.zig
+++ b/src/Scales.zig
@@ -3,6 +3,17 @@ const hlp = @import("helper.zig");
 const Dimensions = @import("Dimensions.zig");
 const Dimension = @import("Dimensions.zig").Dimension;
 
+/// Use to initiate Scalar and Scales type
+pub const ArgOpts = struct {
+    L: UnitScale = .none,
+    M: UnitScale = .none,
+    T: UnitScale = .none,
+    I: UnitScale = .none,
+    Tp: UnitScale = .none,
+    N: UnitScale = .none,
+    J: UnitScale = .none,
+};
+
 /// SI prefix (pico…peta) plus time-unit aliases (min, hour, year).
 /// The integer value encodes the exponent for SI prefixes (e.g. `k = 3` → 10³),
 /// and the literal factor for time units (e.g. `hour = 3600`).
@@ -62,9 +73,9 @@ const Scales = @This();
 
 data: std.EnumArray(Dimension, UnitScale),
 
-/// Create a `Scales` from an anonymous struct literal, e.g. `.{ .L = .k, .T = .hour }`.
+/// Create a `Scales` from a struct literal, e.g. `.{ .L = .k, .T = .hour }`.
 /// Unspecified dimensions default to `.none` (factor 1).
-pub fn init(comptime init_val: anytype) Scales {
+pub fn init(comptime init_val: ArgOpts) Scales {
     comptime var s = Scales{ .data = std.EnumArray(Dimension, UnitScale).initFill(.none) };
     inline for (std.meta.fields(@TypeOf(init_val))) |f| {
         if (comptime hlp.isInt(@TypeOf(@field(init_val, f.name))))
diff --git a/src/Vector.zig b/src/Vector.zig
index cce42b8..54657b2 100644
--- a/src/Vector.zig
+++ b/src/Vector.zig
@@ -2,6 +2,7 @@ const std = @import("std");
 const hlp = @import("helper.zig");
 
 const Scalar = @import("Scalar.zig").Scalar;
+const Scalar_ = @import("Scalar.zig").Scalar_;
 const Scales = @import("Scales.zig");
 const UnitScale = Scales.UnitScale;
 const Dimensions = @import("Dimensions.zig");
@@ -32,13 +33,13 @@ pub fn Vector(comptime len: usize, comptime Q: type) type {
         }
 
         /// Element-wise addition. Dimensions must match; scales resolve to the finer of the two.
-        pub inline fn add(self: Self, rhs: anytype) Vector(len, Scalar(
+        pub inline fn add(self: Self, rhs: anytype) Vector(len, Scalar_(
             T,
             dims,
             hlp.finerScales(Self, @TypeOf(rhs)),
         )) {
             const Tr = @TypeOf(rhs);
-            var res: Vector(len, Scalar(T, d, hlp.finerScales(Self, @TypeOf(rhs)))) = undefined;
+            var res: Vector(len, Scalar_(T, d, hlp.finerScales(Self, @TypeOf(rhs)))) = undefined;
             inline for (self.data, 0..) |v, i| {
                 const q = (Q{ .value = v }).add(Tr.ScalarType{ .value = rhs.data[i] });
                 res.data[i] = q.value;
@@ -46,13 +47,13 @@ pub fn Vector(comptime len: usize, comptime Q: type) type {
             return res;
         }
         /// Element-wise subtraction. Dimensions must match; scales resolve to the finer of the two.
-        pub inline fn sub(self: Self, rhs: anytype) Vector(len, Scalar(
+        pub inline fn sub(self: Self, rhs: anytype) Vector(len, Scalar_(
             T,
             dims,
             hlp.finerScales(Self, @TypeOf(rhs)),
         )) {
             const Tr = @TypeOf(rhs);
-            var res: Vector(len, Scalar(T, d, hlp.finerScales(Self, @TypeOf(rhs)))) = undefined;
+            var res: Vector(len, Scalar_(T, d, hlp.finerScales(Self, @TypeOf(rhs)))) = undefined;
             inline for (self.data, 0..) |v, i| {
                 const q = (Q{ .value = v }).sub(Tr.ScalarType{ .value = rhs.data[i] });
                 res.data[i] = q.value;
@@ -64,13 +65,13 @@ pub fn Vector(comptime len: usize, comptime Q: type) type {
         pub inline fn divBy(
             self: Self,
             rhs: anytype,
-        ) Vector(len, Scalar(
+        ) Vector(len, Scalar_(
             T,
             dims.sub(@TypeOf(rhs).dims),
             hlp.finerScales(Self, @TypeOf(rhs)),
         )) {
             const Tr = @TypeOf(rhs);
-            var res: Vector(len, Scalar(T, d.sub(Tr.dims), hlp.finerScales(Self, @TypeOf(rhs)))) = undefined;
+            var res: Vector(len, Scalar_(T, d.sub(Tr.dims), hlp.finerScales(Self, @TypeOf(rhs)))) = undefined;
             inline for (self.data, 0..) |v, i| {
                 const q = (Q{ .value = v }).divBy(Tr.ScalarType{ .value = rhs.data[i] });
                 res.data[i] = q.value;
@@ -82,13 +83,13 @@ pub fn Vector(comptime len: usize, comptime Q: type) type {
         pub inline fn mulBy(
             self: Self,
             rhs: anytype,
-        ) Vector(len, Scalar(
+        ) Vector(len, Scalar_(
             T,
             dims.add(@TypeOf(rhs).dims),
             hlp.finerScales(Self, @TypeOf(rhs)),
         )) {
             const Tr = @TypeOf(rhs);
-            var res: Vector(len, Scalar(T, d.add(Tr.dims), hlp.finerScales(Self, @TypeOf(rhs)))) = undefined;
+            var res: Vector(len, Scalar_(T, d.add(Tr.dims), hlp.finerScales(Self, @TypeOf(rhs)))) = undefined;
             inline for (self.data, 0..) |v, i| {
                 const q = (Q{ .value = v }).mulBy(Tr.ScalarType{ .value = rhs.data[i] });
                 res.data[i] = q.value;
@@ -100,12 +101,12 @@ pub fn Vector(comptime len: usize, comptime Q: type) type {
         pub inline fn divByScalar(
             self: Self,
             scalar: anytype,
-        ) Vector(len, Scalar(
+        ) Vector(len, Scalar_(
             T,
             dims.sub(@TypeOf(scalar).dims),
             hlp.finerScales(Self, @TypeOf(scalar)),
         )) {
-            var res: Vector(len, Scalar(T, d.sub(@TypeOf(scalar).dims), hlp.finerScales(Self, @TypeOf(scalar)))) = undefined;
+            var res: Vector(len, Scalar_(T, d.sub(@TypeOf(scalar).dims), hlp.finerScales(Self, @TypeOf(scalar)))) = undefined;
             inline for (self.data, 0..) |v, i| {
                 const q = Q{ .value = v };
                 res.data[i] = q.divBy(scalar).value;
@@ -117,12 +118,12 @@ pub fn Vector(comptime len: usize, comptime Q: type) type {
         pub inline fn mulByScalar(
             self: Self,
             scalar: anytype,
-        ) Vector(len, Scalar(
+        ) Vector(len, Scalar_(
             T,
             dims.add(@TypeOf(scalar).dims),
             hlp.finerScales(Self, @TypeOf(scalar)),
         )) {
-            var res: Vector(len, Scalar(T, d.add(@TypeOf(scalar).dims), hlp.finerScales(Self, @TypeOf(scalar)))) = undefined;
+            var res: Vector(len, Scalar_(T, d.add(@TypeOf(scalar).dims), hlp.finerScales(Self, @TypeOf(scalar)))) = undefined;
             inline for (self.data, 0..) |v, i| {
                 const q = Q{ .value = v };
                 res.data[i] = q.mulBy(scalar).value;
@@ -132,7 +133,7 @@ pub fn Vector(comptime len: usize, comptime Q: type) type {
 
         /// Standard dot product. Dimensions are summed (e.g., Force * Distance = Energy).
         /// Returns a Scalar type with the combined dimensions and finest scale.
-        pub inline fn dot(self: Self, rhs: anytype) Scalar(
+        pub inline fn dot(self: Self, rhs: anytype) Scalar_(
             T,
             dims.add(@TypeOf(rhs).dims),
             hlp.finerScales(Self, @TypeOf(rhs)),
@@ -150,7 +151,7 @@ pub fn Vector(comptime len: usize, comptime Q: type) type {
 
         /// 3D Cross product. Dimensions are summed.
         /// Only valid for vectors of length 3.
-        pub inline fn cross(self: Self, rhs: anytype) Vector(3, Scalar(
+        pub inline fn cross(self: Self, rhs: anytype) Vector(3, Scalar_(
             T,
             dims.add(@TypeOf(rhs).dims),
             hlp.finerScales(Self, @TypeOf(rhs)),
@@ -159,7 +160,7 @@ pub fn Vector(comptime len: usize, comptime Q: type) type {
                 @compileError("Cross product is only defined for Vector(3, ...)");
 
             const Tr = @TypeOf(rhs);
-            const ResScalar = Scalar(T, d.add(Tr.dims), hlp.finerScales(Self, Tr));
+            const ResScalar = Scalar_(T, d.add(Tr.dims), hlp.finerScales(Self, Tr));
             const ResVec = Vector(3, ResScalar);
 
             // Calculation: [y1*z2 - z1*y2, z1*x2 - x1*z2, x1*y2 - y1*x2]
@@ -202,7 +203,7 @@ pub fn Vector(comptime len: usize, comptime Q: type) type {
 
         /// Multiplies all components of the vector together.
         /// Resulting dimensions are (Original Dims * len).
-        pub inline fn product(self: Self) Scalar(
+        pub inline fn product(self: Self) Scalar_(
             T,
             dims.scale(len),
             scales,
@@ -215,12 +216,12 @@ pub fn Vector(comptime len: usize, comptime Q: type) type {
 
         /// Raises every component to a compile-time integer power.
         /// Dimensions are scaled by the exponent.
-        pub inline fn pow(self: Self, comptime exp: comptime_int) Vector(len, Scalar(
+        pub inline fn pow(self: Self, comptime exp: comptime_int) Vector(len, Scalar_(
             T,
             dims.scale(exp),
             scales,
         )) {
-            const ResScalar = Scalar(T, dims.scale(exp), s);
+            const ResScalar = Scalar_(T, dims.scale(exp), s);
             var res: Vector(len, ResScalar) = undefined;
             inline for (self.data, 0..) |v, i| {
                 const q = Q{ .value = v };
@@ -436,16 +437,8 @@ pub fn Vector(comptime len: usize, comptime Q: type) type {
 }
 
 test "Format VectorX" {
-    const MeterPerSecondSq = Scalar(
-        f32,
-        Dimensions.init(.{ .L = 1, .T = -2 }),
-        Scales.init(.{ .T = .n }),
-    );
-    const KgMeterPerSecond = Scalar(
-        f32,
-        Dimensions.init(.{ .M = 1, .L = 1, .T = -1 }),
-        Scales.init(.{ .M = .k }),
-    );
+    const MeterPerSecondSq = Scalar(f32, .{ .L = 1, .T = -2 }, .{ .T = .n });
+    const KgMeterPerSecond = Scalar(f32, .{ .M = 1, .L = 1, .T = -1 }, .{ .M = .k });
 
     const accel = MeterPerSecondSq.Vec3.initDefault(9.81);
     const momentum = KgMeterPerSecond.Vec3{ .data = .{ 43, 0, 11 } };
@@ -459,7 +452,7 @@ test "Format VectorX" {
 }
 
 test "VecX Init and Basic Arithmetic" {
-    const Meter = Scalar(i32, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
+    const Meter = Scalar(i32, .{ .L = 1 }, .{});
     const Vec3M = Meter.Vec3;
 
     // Test zero, one, initDefault
@@ -500,8 +493,8 @@ test "VecX Init and Basic Arithmetic" {
 }
 
 test "VecX Kinematics (Scalar Mul/Div)" {
-    const Meter = Scalar(i32, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
-    const Second = Scalar(i32, Dimensions.init(.{ .T = 1 }), Scales.init(.{}));
+    const Meter = Scalar(i32, .{ .L = 1 }, .{});
+    const Second = Scalar(i32, .{ .T = 1 }, .{});
     const Vec3M = Meter.Vec3;
 
     const pos = Vec3M{ .data = .{ 100, 200, 300 } };
@@ -525,7 +518,7 @@ test "VecX Kinematics (Scalar Mul/Div)" {
 }
 
 test "VecX Element-wise Math and Scaling" {
-    const Meter = Scalar(i32, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
+    const Meter = Scalar(i32, .{ .L = 1 }, .{});
     const Vec3M = Meter.Vec3;
 
     const v1 = Vec3M{ .data = .{ 10, 20, 30 } };
@@ -540,8 +533,8 @@ test "VecX Element-wise Math and Scaling" {
 }
 
 test "VecX Conversions" {
-    const KiloMeter = Scalar(i32, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = .k }));
-    const Meter = Scalar(i32, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
+    const KiloMeter = Scalar(i32, .{ .L = 1 }, .{ .L = .k });
+    const Meter = Scalar(i32, .{ .L = 1 }, .{});
 
     const v_km = KiloMeter.Vec3{ .data = .{ 1, 2, 3 } };
     const v_m = v_km.to(Meter);
@@ -556,8 +549,8 @@ test "VecX Conversions" {
 }
 
 test "VecX Length" {
-    const MeterInt = Scalar(i32, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
-    const MeterFloat = Scalar(f32, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
+    const MeterInt = Scalar(i32, .{ .L = 1 }, .{});
+    const MeterFloat = Scalar(f32, .{ .L = 1 }, .{});
 
     // Integer length
     // 3-4-5 triangle on XY plane
@@ -572,8 +565,8 @@ test "VecX Length" {
 }
 
 test "Vector Comparisons" {
-    const Meter = Scalar(f32, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
-    const KiloMeter = Scalar(f32, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = .k }));
+    const Meter = Scalar(f32, .{ .L = 1 }, .{});
+    const KiloMeter = Scalar(f32, .{ .L = 1 }, .{ .L = .k });
 
     const v1 = Meter.Vec3{ .data = .{ 1000.0, 500.0, 0.0 } };
     const v2 = KiloMeter.Vec3{ .data = .{ 1.0, 0.5, 0.0 } };
@@ -601,8 +594,8 @@ test "Vector Comparisons" {
 }
 
 test "Vector vs Scalar Comparisons" {
-    const Meter = Scalar(f32, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
-    const KiloMeter = Scalar(f32, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = .k }));
+    const Meter = Scalar(f32, .{ .L = 1 }, .{});
+    const KiloMeter = Scalar(f32, .{ .L = 1 }, .{ .L = .k });
 
     const positions = Meter.Vec3{ .data = .{ 500.0, 1200.0, 3000.0 } };
     const threshold = KiloMeter{ .value = 1.0 }; // 1km (1000m)
@@ -621,8 +614,8 @@ test "Vector vs Scalar Comparisons" {
 }
 
 test "Vector Dot and Cross Products" {
-    const Meter = Scalar(f32, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
-    const Newton = Scalar(f32, Dimensions.init(.{ .M = 1, .L = 1, .T = -2 }), Scales.init(.{}));
+    const Meter = Scalar(f32, .{ .L = 1 }, .{});
+    const Newton = Scalar(f32, .{ .M = 1, .L = 1, .T = -2 }, .{});
 
     const pos = Meter.Vec3{ .data = .{ 10.0, 0.0, 0.0 } };
     const force = Newton.Vec3{ .data = .{ 5.0, 5.0, 0.0 } };
@@ -645,7 +638,7 @@ test "Vector Dot and Cross Products" {
 }
 
 test "Vector Abs, Pow, Sqrt and Product" {
-    const Meter = Scalar(f32, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
+    const Meter = Scalar(f32, .{ .L = 1 }, .{});
 
     const v1 = Meter.Vec3{ .data = .{ -2.0, 3.0, -4.0 } };