The Micro Brake is ideal for a short, lightweight single port muzzle brake suited for a variety of platforms. 1/2-28: .38 Bore The Micro muzzle devices are designed to be used with the KeyMicro Adapter giving your Ghost, Wolf, or Wolfman a quick attach functionality similar to our proven KeyMo system. It is also compatible with Dead Airs existing KeyMo system. Length of a Micro Brake is: 2.06″