The Gentry Custom Quiet Muzzle Brake does a very effective job of mitigating recoil and muzzle jump in a classic style. These 6.5mm Quiet Muzzle Brakes are available in polished blue, matte blue, or stainless steel with a 5/8-24 thread pitch. 6.5mm 5/8-24 thread pitch .875" outside diameter 2.5" long The installation of a Quiet Muzzle Brake does not impact the firearm's velocity or accuracy. Mfg: Gentry Custom