Ruger Hybrid Muzzle Brake 35 Cal Matte Black Steel. 35 Caliber Hybrid Muzzle Brake reduces recoil and muzzle rise contributing to improved accuracy over a longer string of fire. It also reduces noise and debris by directing the blast to the sides of the shooter. The brake is timed using the crush washer (2 included) and installs quickly using a 7/8" box wrench or crescent wrench. It is manufactured from 4140 chrome molly steel with a matte black finish. It fits rifles with "-28 x .400 length threads chambered in .350 Legend including the AR-556 and the Ruger American Rifle Ranch and the PC Carbine chambered in 9mm. Specifications for Ruger 90698 Hybrid Muzzle Brake 35 Cal Matte Black Steel: Manufacturer: Ruger Finish: Matte Black Fabric/Material: Steel Condition: New