Features: Multi-port design reduces felt recoil up to 76% (depending on caliber) Top and side ports direct gases to reduce muzzle rise Closed bottom design reduces dust signature during firing Rugged all-steel construction Multi-caliber design fits X-Bolt Speed rifles and most sporter-weight rifle barrels .30 caliber or smaller with an M13x1.25 or M13x.75 threaded muzzle