Own the same rear sight/EoTech mount used by the FBI's Hostage Rescue Team and SWAT. It fits any Picatinney railed AR upper. The rear sight is the standard A2-type with a 6/3 elevation drum and dual apertures.
This one is like new. I never mounted my EOTech to it. Order one from Rock River and it will set you back $175 + shipping. Own this one for $95 shipped to CONUS.