it's a $20 coleman from walmart. 90 lumens output,comes w red and blue lenses. I modified it using a pressure switch from an old laser sight I had on my .22cal. Lengthened the wires on the switch and,after drilling a hole in the tail cap,ran one wire to +,and one to - side of battery pak.then put a 5/16x24 bolt through the tailcap. The bracket is a 6" piece of 3/8"x1/8" of flatbar from home depot. The way I've gor it set-up in the pic,it balances beautifully at the shot. I sacrificed a sims S-coil to mount between the light and bracket. It's very quiet and works great.
I've also got a 230 lumen ultrafire that will mount on a picatinny rail to go on my Athens. That one shines bright out to 100+ yards.