6315XE-S (Xeno) is a Dead Air Xeno compatible muzzle device threaded for 1/2 x 28. Based on the successful 6315 design that features smaller and shorter 3 o'clock and 9 o'clock ports and provides 15 to 20% better compensator performance over TDP spec A2 compensator (Army designation), all without incurring additional concussion, noise and flash suppression, 6315XE is a closed bottom flash suppressor that reduces dust signature when shooting from prone.6315XE-S is 1.9" long (the full sized 6315XE is 2.157" long), and has a pin hole for pinning it to a barrel. Assuming 0.5" of threads on the barrel for muzzle devices, 6315XE will add 1.4" to the barrel, and with 0.1" or 0.2" of shims (such as the Precision Armament shims kit) bring a 14.5" barrel to over 16". A pin hole is drilled on the bottom for pinning 6315XE to the barrel.6315XE-S is a solid candidate for SBRs, and for users that want their rifles as short as possible. Shortening the flash suppressor/compensator component of the muzzle hasn't impacted its flash suppression and muzzle rise compensator performance. For more information, please visit this page in our FAQ section: Size doesn't matter, sometimes All of the short muzzle devices share nearly identical performance: 6315RF, 6310RF, 6315XE-S 6315KM-S (both 9mm and 223).COMPATIBLE ADAPTER(S) :Xeno adapterCOMPATIBLE SILENCER(S):Nomad series with Xeno adapterNomad-Ti series with Xeno adapterPrimal with Xeno adapterWolfman with Xeno P-Series adapterSierra-5