The Rear End by Q is a Quickie Fast-Attach muzzle brake compatible with the THUNDER CHICKEN and trash PANDA silencers by Q. The Rear End series of mounts feature a 90* shoulder. Along with the 90* shoulder we included wrench flats in the rear just in case your Rear End gets stuck in your silencer. Included on the Cherry Bomb style Rear End's is inch socket features in the front this is the preferred method of install/uninstall and the rear flats are there just in case your Rear End gets stuck in your silencer. WEIGHT: 2.0 oz. OVERALL LENGTH: 1.71" MATERIAL: 17-4 Stainless Steel LENGTH ADDED TO BARREL: 0.8Prime; 9mm Bore