BREEK ARMS PLAN B ECHO 30 CALIBER SINGLE-PORT MUZZLE BRAKE Ultra-compact single-port design for the Plan B mounting system. The Breek Arms Plan B Echo Single-Port Muzzle Brake significantly reduces recoil and muzzle rise through 90Adeg horizontal blast-vectoring ports -keeping your rifle flat, fast, and ready for seamless suppressor swaps. SPECS Weight: 2.0 oz. Overall Length: 1.75" Material: 4140 Hardened Steel, Nitride Thread Pitch: 5/8 x 24 TPI Caliber: .30 CAL Fast attach for Plan B suppressor mounts Mfg: Breek Arms