The AR-15 Crush Washer with 5/8" threading is an essential component for proper muzzle device installation and timing on AR-15 rifles.AR-15 Crush Washer with 5/8" threadingEnsures proper muzzle device alignment and timingSingle-use washer for secure installationCompatible with standard AR-15 muzzle threadsDesigned for gunsmith and enthusiast use when installing muzzle brakes flash hiders or compensators on AR-15 platform rifles.