Headlamp Assembly (12 Volt), Dim A (1): 6″ Diameter, Dim B (2): Red Enamel Steel Body, Dim C (3): 4 Wires: Black – Ground, Red – Bright, Yellow – Dim, White – Parking, Dim D (4): Not Necessary To Use All Wires If Not Needed. For Basic Work Light Use Black & Red Wires Only.