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 degree shoulder. Along with the 90 degree shoulder include wrench flats in the rear just in case the Rear End gets stuck in the silencer. Included on the Cherry Bomb style Rear End’s is 1/2 inch socket features in the front this is the preferred method of install/uninstall and the rear flats are there just in case the Rear End gets stuck in the silencer. Wrench Flats Size 11/16 inch for 1/2×28 threads.