"I got this thing deciding to try and put it on my KWC Desert Eagle. I thought why not, it's only $16 right? Well, I get the thing and after a few minutes of looking at it...it worked! I was able to screw it on perfectly tight and slap it in the holster just fine. Be aware though, since it is a push switch, it can be bumped around and turn on at will. Just something to note, other than that, this thing works great for night engagement, though not so much for day.
Easy to dial in
Heck of a lot easier than using iron sights
Can be turned on in holster (just watch it or get more batteries)
All in all, very satisfied with this product, if it can fit a Desert Eagle, I'm pretty sure it can fit just about any other pistol out there...