SpecialFire&reg; CREE XM-L U2 Flashlight Drop-in LED Bulb 3 Mode 1000Lumens 3.7-4.2V for Ultrafire 501B 502B Surefire 6P 9P D2 Comes with a lifetime warranty if purchase through ArizonaTacticalGear Voltage Range 3-8v. Increase your brightness up to 1200 lumens with this US made CREE XML-U2 Save batteries with 2-3 times the run-time over normal incandescent 3 Modes of Operation (High, Low, Strobe) controlled with soft click of tail switch Smooth reflector for extreme ilumination distance and tightly focused beam