Forward Controls Design Flash Hider .223 Remington 1/2x28 Nitride Black. Threaded for 1/2 x 28 (internal) and M22 x 1 (external) 6315AE is compatible with all Allen Engineering .223 sound suppressors such as AEM2 AEM3 AEM4 and AEM5 (except for direct thread models such as M4 and M24) 6315AE is a 6315 (introduced in 2017) that's been designed to accept Allen Engineering 223 sound suppressors. 6315 itself is based on the TDP A2 compensator (Army 23&P designation) and features smaller 3 and 9 o'clock ports which force more gas to be vented through the top 3 ports. Throughout the years we've added small improvements to it the most notable is the internal grooves that help keep the flash inside the cone cavity instead of outside of the muzzle device. Flats are incorporated for standard AR15/M16 armorer's wrench or 3/4in wrench for installation. Do not use a crush washer if this is going to be a suppressor host. Specifications for Forward Controls Design 6315AE Flash Hider: Manufacturer: Forward Controls Design Color: Black Caliber: .223 Remington Finish: Nitride Fabric/Material: 4140 Steel Threads per Inch: 1/2x28 Length: 1.88 in Weight: 2.3 oz Package Contents: Forward Controls Design 6315AE Flash Hider Single use packet of Rocksett Forward Controls Design 6315AE: 6315AE Flash Hider .223 Remington 1/2x28 Nitride Black