I recently installed this one on my .40 carbine. I figure for $35 range it's worth a gamble... Apparently they're from China but the build quality is decent considering the price, and the light is VERY bright. A couple of the feedback guys say they've used them successfully with hundreds of rounds, and the positive comments outweigh the negative by quite a bit. I'm not even going to mess with the dubious pressure switch which seems responsible for many of the negative comments. Anyhow, I'll probably be posting a range report in a couple weeks.
Note: It doesn't ship with a battery.
http://www.amazon.com/Tactical-Green...7175486&sr=1-1