The only one I know of I LaserMax. I have one for my Glock 23, and like it a lot. I doubt that I would use it in a gunfight, but it's fun to use at the range, and could be very intimidating if you just wanted to scare someone (ie, someone threatening you with a knife at 25 feet or more). It's very accurate, and LaserMax's customer service is excellent. You can generally pick them up for around 300-350. Check Ebay.