First off, it's a great product. The optical clarity is great. Now I'll explain my "cons" statement a bit: I installed it on my Robinson Arms XCR, which already has an Eotech 3-0 holosight. This issue, after a lot of "working the issue," seems to be that the ARMS mount itself tilts the magifier back ever so slightly upon swinging the tightening lever closed. While barely visible to the naked eye (if at all visible), it shows up when looking through the magnifier...the holosight reticle was in the very bottom of the magnifier "frame" of view. NOW the great thing that this Eotech magnifier has, which I bet the imitation ones don't have, is the ability to adjust the magnifier glass upwards/downwards as well as side to side, so that you can center the reticle within the magnifier.
The process is to sight the holosight in first, then mount the magnifier, then center the reticle within the magnifier "frame" through that you look through.
So you would think this would solve my problem. It did, but only after adjusting the glass of the magnifier to the maximum vertical extent...in other words, the screw used to adjust it (by turning the screw) was screwed all the way in.
So, it is perfectly aligned now, but clearly it shouldn't have had to been adjusted so much.
I truly hope that this is simply a problem with the ARMS mount on my specific unit. I know Eotech is a great company and I hope the unit you get doesn't have this problem.
Pros: clarity, adjustability
Cons: the ARMS mount tilts the entire magifier back
This review was written in the old system and had content requirements that are different than reviews written today.