Rating: 5.56, 300BLK, 7.62×39, 9X39, 350 Legend, (When shooting supersonic rifle ammo you must use the KeyMicro brake, semi-auto only rated on supersonic rifle cartridges. Full-auto rated on everything else) .380, 9mm Length (Long, no mount): 7.5″ Length (Short, no mount): 5.13″ Weight (Long, no mount): 14.4 oz. Weight (Short, no mount): 9.8 oz. Diameter: 1.618″ Finish: Cerakote Mount: Ships with 1/2-28 direct-thread insert