P15D-30 LED Headlight 12 Volt 30 SMD. Works either positive ground or negative ground. UP to 400 Lumens. The smd are positioned where the filament would be for optimal light output. The lamp is dim-able using a varying voltage source. The max voltage is 14.2. Super long life up to 30,000 hours. Made with 5730 smd for maximum output. The base diameter is 15mm. The ring is 30mm. There are two contacts. Please make sure that you have a voltage regulator in your headlight circuit for your vintage bike or the led headlight will fail due to over voltage. One contact is for low beam. One contact for high beam. CE and Rohs. Other names DC prefocus, double contact prefocus or double contact candelabra prefocus. The M.O.L. is 1.962" and the diameter is 0.741". This is a NCNRNW Non-Cancelable Non-Returnable Non-Warranty, please see policies for more details. The product is tested before shipping.