Replaces the grip on the right side of Colt-Style 1911 auto frame. “Quad Lock” installation system securely attaches the mount to the frame at four points. Supplied screw Pins replace Hammer and Main Spring Housing pins for supplemental attachment. No drilling or tapping. Instructions include. See at: http://www.brownells.com/optics-mounting/electronic-sights/mounting-hardware/1911-auto-grip-scope-mount-prod63.aspx. Email: kiblerae@cox.net Phone: (757) 547-4017 (H); (757) 535-0111 (C), no call after 8 pm please.