Double muzzle brake for Ruger 10/22 rifles. Easy to install and reduces muzzle rise and recoil from both slots and holes. Slips on around your original front sight post and tightens in place. Requires no gunsmithing and retains your original front sight post. Blue steel and not made by Ruger. Will not fit heavy barrels, target barrels, or International stocked versions. .065 inside diameter. This is a muzzle brake, NOT a flash hider. New in package.