I always had issues of the lens piece falling out of mine while shooting. No matter what I did to keep it in there it fell out. This was while shooting my G22. I gave up on mine and now it sits on a shelf in my closet. I paid a little bit more and got a Streamlight TRL1. Much better light and holsters exist for it.
Glock 22 (LWD .357 Sig barrel), Glock 27, Colt M4
Black Rifle Club member #224 Lone Star Glocker #134
NREMT-Paramedic TCCC Instructor