We set out to solve a problem that has plagued legal firearms owners for years. When taking a barrel to the minimum legal limit with a permanently attached muzzle device, one was forever locked in to their barrel, gas block, and handguard configuration. To us, that's nuts. The SLIM series was designed so that shooters could permanently attach a muzzle device and still get their gas block and barrel nut over the device. SLIM 3-Port Muzzle Brake * Material: Gun Barrel Quality Steel* Finish: QPQ Salt Bath Nitride* Thread: 1/2"-28 TPI* Weight: 1.12 Ounces * Length: 2.125 Inches* Diameter: .620"* Caliber: .223/5.56