KNIGHT'S ARMAMENT QDSS NT4 5.56MM NATO RIFLE SUPPRESSOR The KAC Quick Detach Sound Suppressor (QDSS) NT4 is a combat proven 5.56mm suppressor developed for U.S. Military applications requiring high durability and sustained full auto fire capability. The NT4 provides the user with a quick means to attach and detach the suppressor to the included muzzle device via the precision locking groove on the muzzle device and the gate latch mechanism on the suppressor. The provision of the muzzle device having external carbon cutting grooves, and the front edge alignment notch at the six o'clock position, ensures proper sound suppressor orientation and installation each time Mfg: Knights Armament