The AR-STONER(TM) Precision Muzzle Brake with 5/8" - 24 threads counters the recoil of your AR-10, LR-308, or other 7.62x51/.308 rifle builds. Constructed of solid steel, this muzzle brake has a melonite finish to products against damage from heat and corrosion. Six horizontal ports reduce felt recoil and three top ports lessen muzzle rise. Keep your sights on target with the AR-STONER(TM) Precision Muzzle Brake.FeaturesSolid Steel ConstructionMelonite Finish6 Horizontal Ports3 Top Ports Note: Crush washer is included