this thing is great. it prevents your hand gettin screwed from the normal cockin thing that they give ya with the gun. it is very easy to install if you know your gun. there have not been any seveer problems with it at all
i recomend it if your hand gets constantly pinched on your gun
Weaknesses:
if you tighten the screws to tight the thing wont cock but thats only when it is so tight its hard to take the screws off