I second all the other reviews. I bought this more to be shoulder-strap mountable, ala the XP Adapter kit. If I had a complaint, it could stand to be a tad brighter as I still have to carry a high-intensity hand-held.
Amended: After using this for a year, I will still say that I was expecting it to be brighter. Batteries didn't last as long as I expected from an LED either. Lowered my rating from 5 to 4 stars.