This will work perfectly for the majority of ACOG's, unfortunately, it does not sit deep enough when there is the chassis system for the RMR on my Trijicon. Because it sits a little shallow instead of the flip cap opening the whole unit pops off. I'm still manipulating it, trying to find a permanent fix. So caveat emptor for this if you do have such a set up. Other wise this will do the job perfectly.
Pros: affordable, sturdy
Cons: Not designed for Trijicon's with RMR red dots on top of ACOG
This review was written in the old system and had content requirements that are different than reviews written today.