Watchtower Firearms Dragon Slay AR Muzzle Brake 308/5.56 Cal 5/8x24 PVD Coated Black Nitride. 56 NATO .308 Win. And 9MM greatly reduces muzzle rise with these chamberings. Providing the operator with extreme accuracy and a more comfortable shooting experience. Precision machined from 4140 low-alloy domestic steel the brake also carries a high-end black-nitride finish or is available in a PVD coated finish. Specifications for Watchtower Firearms Dragon Slay AR Muzzle Brake: Manufacturer: Watchtower Firearms Color: Black Nitride Caliber: 5.56x45mm NATO .308 Winchester Finish: PVD Coated Fabric/Material: 4140 Steel Threads per Inch: 5/8x24 Gun Model: AR-15 Length: 2.95 in Weight: 2.59 oz Additional Features: Width: .825in Features of Watchtower Firearms Dragon Slay AR Muzzle Brake AISI/SAE 4140 low-alloy Steel; Package Contents: Watchtower Firearms Dragon Slay AR Muzzle Brake What firearm models does the manufacturer say Watchtower Firearms Dragon Slay AR Muzzle Brake is compatible with? The manufacturer says that Watchtower Firearms Dragon Slay AR Muzzle Brake is compatible with AR-15Watchtower Firearms DS-308-BN: Dragon Slay AR Muzzle Brake 308/5.56 Cal 5/8x24 PVD Coated Black Nitride