I was looking for a 45 degree rail to mount my reflex sight while my scope is the primary optic on my AR-15, this one is pretty well built, stays on once I managed to force it on the rail and holds a reflex sight or tac light. There are higher quality products I'm sure, but for the money this one was not bad.
Pros: great mount for light, laser or red dot
Cons: kind of a hassle to install
This review was written in the old system and had content requirements that are different than reviews written today.