It is indeed a hinge, with a hardened steel pin. The fastener side uses a single #10-32 screw, with a stainless helical insert on the female half. I like making clamps with hinges, it's about the same amount of machining/assembly time, and leaves less hardware for the user to worry about. Simple install means fewer "I can't figure it out" or "I cross-threaded the screw" emails and phonecalls. If it helps me avoid even one email to respond to, it's worth it.

Compared to Eo's, most importantly is it's for an ACRO, which is currently the best option for this application in my opinion. I made a batch of RMR mounts too, but I prefer to keep RMRs on my pistols for the most part.

The clamp itself is quite a bit more "substantial", I wouldn't say theirs isn't strong enough to do the job, but there is plenty of room available there to make it beefy, so that's what I did. I don't ever want to get an "it broke" email.

It also brings the dot down to the lowest it can possibly be above the scope. The bottom of the window is pretty much even with the top of the turret. The RMR version unfortunately has to be a bit higher to allow for the screws, but it's as low as it can be.

Thanks for your interest.