Tiger Rock AR-15/.223/5.56 Birdcage Muzzle Brake for 1/2x28 TPI 5 Ports Cerakote Pink Small. It's constructed of solid 4150 steel and has a high quality. Fitted steel crush-washer not included. Specifications for Tiger Rock AR-15/.223/5.56 Birdcage Muzzle Brake for 1/2x28 TPI: Manufacturer: Tiger Rock Projectile Caliber: .224 Caliber Caliber: 5.56x45mm NATO .223 Remington Finish: Cerakote Fabric/Material: 4150 Steel Threads per Inch: 1/2x28 Gun Make: AR Platform Gun Model: AR-15 Package Contents: Tiger Rock AR-15/.223/5.56 Birdcage Muzzle Brake for 1/2x28 TPI What firearm models does the manufacturer say Tiger Rock AR-15/.223/5.56 Birdcage Muzzle Brake for 1/2x28 TPI is compatible with? The manufacturer suggests that Tiger Rock AR-15/.223/5.56 Birdcage Muzzle Brake for 1/2x28 TPI is compatible with AR-15Tiger Rock MBR05-PNK: AR-15/.223/5.56 Birdcage Muzzle Brake for 1/2x28 TPI 5 Ports Cerakote Pink Small