The PM141B Picatinny scope rail attaches directly to the integral base on the RUGER 10-22 Magnum. The mount allows the use of standard Weaver rings and those for Picatinny rails. Red dot, holographic and other sights may be used as well. The rail is constructed of black oxide, heat treated steel. No permanent modification to the firearm required. All mounting hardware included. 10.5" long.