Volquartsen Picatinny Scope Mount designed to fit Ruger MKI, MKII, MKIII, MKIV and 22/45 pistols. The mount is designed to be a no-gunsmithing mount for those receivers that are drilled and tapped from the factory. CNC-machined from aluminum alloy to mil-spec Picatinny tolerances. The rear sight does not need to be removed to install this mount. Includes three mounting screws.