Knight's Armament 5.56 NT4 QDSS suppressor kit (Black). Addition to bare muzzle: 5.88". Addition to M4QD flash hider: 4.63". Overall length: 6.75". Weight: 19.75oz. Sound reduction: 28dB. Note: If this product is reflected as in-stock it means it's either physically in-stock or allocated and available (serial number is assigned) at my distributor