This Breek Arms 3FO AR15 .223/.556, .30 Flash Hider does not have a pin hole pre drilled for pinning. It comes with a crush washer to fit the device and gives you the option to run a flash hider or muzzle brake while utilizing the Breek Arms Castle Blast Shield as a forward blast diverter or concussion device. Simply slide the blast shield over the outside of the muzzle device and turn the blast shield on.