Forward Controls Design Flash Hider 1/2x28 Nitride Black. Based on the successful 6315 design that features smaller and shorter 3 o'clock and 9 o'clock ports and provides 15 to 20percent 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 1.9in long and has a pin hole for pinning it to a barrel. Assuming 0.5in of threads on the barrel for muzzle devices 6315XE will add 1.4in to the barrel and with 0.1in or 0.2in of shims (such as the Precision Armament shims kit) bring a 14.5in barrel to over 16in. 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). Do not use a crush washer if this is going to be a suppressor host. Specifications for Forward Controls Design 6315XE-S Flash Hider: Manufacturer: Forward Controls Design Color: Black Finish: Nitride Fabric/Material: 4140 Steel Threads per Inch: 1/2x28 Length: 1.9 in Weight: 2.91 oz Package Contents: Forward Controls Design 6315XE-S Flash Hider Single use packet of Rocksett Forward Controls Design 6315XE-S: 6315XE-S Flash Hider 1/2x28 Nitride Black