The KeyMicro Brake is a short, lightweight single port muzzle brake suited for a variety of platforms. Designed for use with our KeyMicro Adapter, it functions as a minimalist brake on its own. Pair them together for the ultimate mounting platform. This is the same technology found in our industry-best KeyMo system. The KeyMicro muzzle devices are also compatible with our KeyMo Adapter. KeyMicro muzzle devices feature a 9mm Bore. Pin & Weld: Not Pre-Drilled Material: 4140 HT Alloy Steel Finish: Black Nitride Thread Pitch: 1/2-28 Weight: 3.41 oz Length: 2.063 Through Bore: 1/2-28: 9MM