This Ruger Muzzle Brake reduces recoil, which contributes to improved accuracy over a longer string of fire. Brake clocks into position using an easy-to-use external jam nut. Reduces noise and blast to the sides of the shooter. Installs quickly using an 7/8" box wrench or crescent wrench. Manufactured from alloy steel with a matte black finish. Fits the Ruger American Rifle Ranch chambered in .450 Bushmaster and Marlin lever-action rifles chambered in .45-70 Govt.