Designed by Faxon's own competition staff, the GUNNER 3 Port Muzzle Brake is the ideal blend of usability, versatility, and recoil reduction. The 3 ports work to sequentially capture the propellant gasses and redirect them to the sides for maximum recoil reduction. On barrels of all lengths, the GUNNER reduces recoil by more than 50%! The GUNNER is 100% 3-Gun Nation, USPSA, and IDPA legal for all divisions.  Product Details: Material: Gun Barrel Quality SteelFinish:  QPQ Salt Bath NitrideThread:  1/2"-28 TPIWeight:  2.9 ounces w/ MuzzLok NutLength:  2.4 inches w/ MuzzLok NutDiameter:  0.9"Caliber:  .223/5.56    MUZZLOK Faxon's invented "Muzzlock" feature on this device allows for easy timing and installation of your device without the need for a crush washer or shims. By using the extension nut to adjust the length of the device, you can adjust the rotational timing. It is recommended that you tighten the device to the recommended torque specification of 20-25 foot pounds. By not having to overcome the resistance of the crush washer, this allows devices to be removed and reinstalled in the field if desired. No crush washer needed. Attach and remove in the field. Time your muzzle device quickly and easily.