Tactical CREE IR NVG Infrared LED Spare Bulb for Ultrafire Surefire 501B 502B and Hugsby Flashlight Torch Etc. Comes with a lifetime warranty if purchase through ArizonaTacticalGear Peak Wave Length : 850nm Runs on 2 x cr123 or 1 x 18650 rechargable battery. 3-7v working range Durable aluminum reflector---Smooth ---Mirror like Never buy bulbs again - LED lifetime over 100,000 hours