Bulb burned out on my E2D Defender. E-Mailed them and they sent another bulb, which normally isn't covered under warranty, free of charge. Hats off to Surefire's customer service. By the way, if you're light ever stops working, and you aren't sure if its the bulb or the switch, take off the endcap (part with the switch) and touch a key to the middle of the battery while simultaneously holding it against the outside of the flashlight. If the light turns on, its the switch/endcap, if it doesn't, it's the bulb.