6315KM-S, 5.56mm is a short Key Micro muzzle device for Dead Air Silencers 5.56mm sound suppressors. At 2.063" long, it's tiny compared to the 6315KM (2.4"). Like 6315 on which it's based, 6315KM-S 5.56mm has asymmetric ports to optimize muzzle rise compensation without creating obnoxious concussion and noise, its 3 and 9 o'clock ports are slightly smaller and shorter, the design forces more gas to be vented through the 3 upward facing ports.6315KM-S is a solid candidate for SBRs, and for users that want their carbines as short as possible. Shortening the flash suppressor/compensator component of the muzzle hasn't unduly impacted its flash suppression and muzzle rise compensator performance.