Update: ordered a RMR rm08g dual illumination and it fit on the mount great. But I sent the site back. Every report about the dual illumination washout is correct and it was worse than i thought. the big green triangle that I wanted so bad would completely and totally disappear when looking from a slightly dark area into a light area (like say, a blind on a sunny day). Guess I will get the battery operated red dot. I wrote trijicon and told them they should recall these sights. The problem is well documented on the Internet and I just wanted to hunt turkey with it, imagine if you used it for self defense on a pistol or shotgun!