This mount came attached to the M1A I bought about a year ago. It was a preban M1A that was covered in dust and looked like it had hardly been fired, and I took the mount off as soon as I got it. It's the 3rd Gen mount, attaches w/ the large screw and fits into the stripper clip guide. I have not used it, obviously in excellent condition. $53 shipped, need $$$ to buy an Aimpoint.