Rugged Suppressors .338 Caliber 3 Port Brake 8.6mm M18x1.5 TPI Dual Taper Locking System. 338 and 8.6 rounds. This muzzle device is designed for reducing recoil when shooting unsuppressed. Compatible with Rugged's Alaskan360 or Alaskan360Ti. You can also use this brake with your 1.37524 threaded suppressor when you pair it with Rugged Suppressors' R.U.M. (Rugged Universal Mount). Timing shims included. Specifications for Rugged Suppressors .338 Caliber 3 Port Brake: Manufacturer: Rugged Suppressors Color: Black Projectile Caliber: .338 Caliber Gun Make: Universal Gun Model: Universal Length: 2.155 in Weight: 2.8 oz Package Contents: Rugged Suppressors .338 Caliber 3 Port Brake What firearm models does the manufacturer say Rugged Suppressors .338 Caliber 3 Port Brake is compatible with? The manufacturer suggests that Rugged Suppressors .338 Caliber 3 Port Brake is compatible with UniversalRugged Suppressors MB027: .338 Caliber 3 Port Brake 8.6mm M18x1.5 TPI Dual Taper Locking System