Scope Mount Cantilever 30mm Tube Diameter; Fits Picatinny RIS; Black; One Piece with extra Picatinny Slots ne piece cantilever designed for better scope alignment and easier eye relief adjustment fits Weaver & Picatinny rails and mounts Integral accessory top and both side rails for mounting laser sight, flashlight and other parts proved to be great if used on cARbines 36.5mm high from its base to its center