Rugged Suppressors Muzzle Brake 3 Ports 1/2X28 Black. 62" Razor 7.62 and Micro30.This muzzle device is designed for reducing recoil when shooting unsuppressed. The 3 Port Brake has a .30 cal aperture" but the 1/2x28 variation can be permanently attached to 5.56 14.5" barrels in order to meet 16" requirements. Specifications for Rugged Suppressors Muzzle Brake 3 Ports 1/2X28: Manufacturer: Rugged Suppressors Color: Black Threads per Inch: 1/2x28 Additional Features: Muzzle Brake 3 ports Features of Rugged Suppressors Muzzle Brake 3 Ports 1/2X28: 30 Cal aperture Package Contents: Rugged Suppressors Muzzle Brake 3 Ports 1/2X28