At only 1.5 oz and 1.3? the M2 Brake is one of the lightest and shortest muzzle brakes on the market. The M2 Brake features Rugged Suppressors' Dual Taper Locking System. The 1/2x28 M2 Brake is compatible up to 9mm on pistol caliber carbines and up to .350 Legend on rifles. Available Thread Pitch Options:5/8x241/2x28 Rugged Suppressors 5/8x24 M2 Brake MB012