Ultimate Arms Gear Tactical Aluminum No Gunsmithing Weaver Picatinny Rail Pistol Scope Mount For Colt .45 1911 Government Frames & Clones Constucted from precision machined aircraft grade aluminum alloy Fits Colt .45 1911 Government Frames And Clones - Easy Installation No Gunsmithing Required Uses Slide Stop Pin To Attach - Fits On The Frame Of The Gun (Not The Grip) For An Ideal Fit Provides A Standard 7/8" 10 Slot See-Thru Designed Weaver - Picatinny Rail For Attaching Scopes, Sights, light, lasers etc. Minimum slide clearance for a sleek look, and elevation adjustment equipped necessary to zero scopes on .45s