"I bought this about 2 months ago and it works great. I've heard that it has a big dot, but on mine it is very small. It has two color settings to choose from (red&green). It's fairly easy to mount and adjust. The only bad things I have to say about this product is that the parts that you use to mount it are very easy to lose (I lost mine), but you can find make-shift ways to put it on without them. The other thing is that on mine, the back part (the little box thing) moves back and forth when you press on it, but it doesn't flop back and forth, which is good. When I move it back and forth it adjusts the size of the dot, which is pointless, kinda cool, but still pointless."