NC Star is coming out with one. It might already be out? Might want to call and ask. But it is a laser that attaches to the picatinny rail and it has a rail built into it. Only difference, the one you pictured is has a green laser, which tend to cost more, and this one looks to be red?
http://www.ncstar.com/newitems.html<<< When there, just click on Flashlights & Lasers and it will take you right to it... Since you didn't specify what bran or how much the one you pictured is, I can't tell you if it is cheaper or not???
P.S. It looks like the one you pictured says the brand on it, but I can't make it out.