Ruger

This .223 Rem / 5.56 NATO Radial Port Muzzle Brake muzzle brake's design reduces felt recoil and muzzle movement. It is made from alloy steel with a black oxide finish to complement most firearms. Installs with a 11/16 open end wrench or crescent wrench. - Torque the brake to 15-20 ft-lbs. - no crush washers are required. - This brake is compatible with AR-556 rifles and other .223 Rem / 5.56 NATO caliber firearms with -28 muzzle threads. Dimensions: 1-3/4 length .75 diameter. Weight: 1.7 ounces. Made in the USA by Swan Manufacturing.