Outerwild AR15 5.56 Flash Hider 1/2x28 Thread Black Nitirde. 5in barrels adds 1.75in of length to the barrel when pinned and welded with a crush washer. Machined from 4140 bar stock Blacknitride+ treated for durability and solid on the bottom to reduce ground disturbance. AR15 Muzzle Brake. Specifications for Outerwild AR15 5.56 Flash Hider: Manufacturer: Outerwild Color: Black Caliber: 5.56mm Finish: Nitirde Fabric/Material: 4140 Bar Stock Threads per Inch: 1/2x28 Gun Make: AR Platform Gun Model: AR-15 Length: 14.5 in Outer Diameter: 1.75 in Condition: New Package Contents: Outerwild AR15 5.56 Flash Hider crush washer What firearm models does the manufacturer say Outerwild AR15 5.56 Flash Hider is compatible with? The manufacturer suggests that Outerwild AR15 5.56 Flash Hider is compatible with AR-15Outerwild 4017-0301-105-O: AR15 5.56 Flash Hider 1/2x28 Thread Black Nitirde