Truck-Lite 44212Y Super 44 Yellow 42 Diode Pattern Integral Strobe Lamp 44212Y Metailized Reflector version offers more intense focused light External power pack not required Dual or quad flashing patterns , Meets recommended SAE J1318 & J845 photometric specifications Synchronized alternating feature, Lamp life rated at 100,000 hours Resistance to shock & vibration, Fit'N Forget adapter plug provides corrosion & moisture resistance