Threads: 1/2x28 5/8x24 - Weight: 3.7 oz.-4.2 oz. - Length: 2.6 - The Keymount Muzzle Brake is your gateway to silence. When youre ready for peace and quiet use the Keymount brake to quickly attach your Sandman-L or Sandman-S to your rifle. If youre not quite ready to turn up the silence you can still employ the finest brake on the market and experience a flatter shooting rifle with minimal concussion compared to traditional muzzle brakes.