Spikes SBV1017 Dynacomp Extreme 5.56mm 1/2"x28 TPI 303 Stainless Black Melonite The Spike's Tactical Dynacomp is a muzzle device designed to reduce recoil impulse and muzzle climb to provide faster follow up shots. The Dynacomp accomplishes this by balancing the direction of the blast along the vertical (upward) and perpendicular planes of the muzzle to lower muzzle rise, while the end of the device restricts forward energy to reduce parallel recoil. The ports on the Dynacomp are ball dimpled for smooth expansion of gases and rapid heat dissipation. The front of the device is 0.25" thick to better handle the abuse of full auto fire. This model is for 5.56 rifles and is threaded for 1/2"x28 barrels. It is machined from 303 Stainless Steel and features a black Melonite finish. It comes with the crush washer needed for installation. Type: Muzzle Brake Model: Dynacomp Extreme Finish: Black Melonite Size: 5.56mm Material: 303 Stainless Steel Thread Pattern: 1/2"-28 tpi