This is exactly what I was looking for. Installed it on my Glock 19. Had it dialed in from 10 yards after 50 rounds. I've shot it 3 times since and it's helds it mark, which I was concerned about based on other reviews. Only improvement would be a smoother toggle swithch.
Pros: Easy to install, operate and dial.
Cons: On switch is somewhat stiff.
This review was written in the old system and had content requirements that are different than reviews written today.