The dome on the LED is a soft gummy material. Once in the flashlight it should last almost indefinately, but if you mishandle it before installing it and knock them dome off or try to wipe it with a cloth and damage it the led will be ruined. In order to replace it you can either send it back to gene or solder a new one on yourself. That's inexpensive (a couple bucks at most) but will take a bit of skill at soldering to do properly.