Spikes Tactical SBV1019 Dynacomp Extreme muzzle brake for .308 rifles. Threaded for 5/8-24 TPI. Made from 416 stainless steel with Black Melonite finish. Features ball-dimpled ports to smooth gas expansion and rapid heat dissipation. The front of the device is 0.25 inches thick to withstand the abuse of full auto fire. Includes crush washer for installation.