Faxon Firearms 5.56 3-Port Muzzle Brake Steel QPQ Nitride Black Small. 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 percent The GUNNER is 100 percent 3-Gun Nation USPSA and IDPA legal for all divisions. Product Details: Material: Steel Finish: Salt Bath Nitride Thread: 1/2"-28 TPI Weight: 2.9 ounces w/ MuzzLok Nut Length: 2.4 inches w/ MuzzLok Nut Diameter: 0.9" Caliber: .223/5.56 MUZZLOK Faxon's invented "Muzzlok" 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. Specifications for Faxon Firearms 5.56 3-Port Muzzle Brake Steel QPQ Nitride: Manufacturer: Faxon Firearms Color: Black Caliber: 5.56x45mm NATO Finish: Salt Bath Nitride Fabric/Material: Steel Threads per Inch: 1/2x28 Gun Model: AR-15 Length: 2.4 in Weight: 2.9 oz Condition: New Diameter: 0.9 in Package Contents: Faxon Firearms 5.56 3-Port Muzzle Brake Steel QPQ Nitride What firearm models does the manufacturer say Faxon Firearms 5.56 3-Port Muzzle Brake Steel QPQ Nitride is compatible with? The manufacturer suggests that Faxon Firearms 5.56 3-Port Muzzle Brake Steel QPQ Nitride is compatible with AR-15Faxon Firearms FFMD5563PMBSQPQ: 5.56 3-Port Muzzle Brake Steel QPQ Nitride Black Small