Precision Reflex Allen Engineering Military Brake with Collar 5.56mm Black. 56 AE brake is designed to work with or without a suppressor. When fired without the suppressor the muzzle brake effectively reduces recoil and muzzle climb. The muzzle brake as designed eliminates upward and downward blast while reducing recoil The brake is constructed of stainless steel and has a 1/2 x 28 thread. The overall length of the brake is 2.125in Specifications for Precision Reflex Allen Engineering Military Brake w/Collar 5.56mm: Manufacturer: Precision Reflex Color: Black Finish: Oxide Fabric/Material: Stainless Steel Condition: New Package Contents: Precision Reflex Allen Engineering Military Brake w/Collar 5.56mm Precision Reflex 05-0090: Allen Engineering Military Brake with Collar 5.56mm Black