Spikes Tactical R2 - HVS Brake 5.56 - Melonite. V.S. muzzle brake is threaded for Spike's Tactical MRS/LRS suppressors. It can also be used for AE/OPS Inc.suppressors models M4s14th 15th 16th and 12th. Specifications for Spikes Tactical R2 Brake - H.V.S.: Manufacturer: Spikes Tactical Color: Black Finish: Black Nitride Fabric/Material: Tool Steel Country of Origin: USA Features of Spikes Tactical R2 Brake - H.V.S.: 1/2x28 Material: Machined from Proprietary Tool Steel Features: Large Side Ports Finish: Black Nitride Finish Thread Pitch: 1/2 X 28 Thread Pitch Includes: 1/2in Muzzle Device Alignment Kit Weight: 1.9oz 5/8x24 Material: Machined from Proprietary Tool Steel Features: Large Side Ports Finish: Black Nitride Finish Thread Pitch: 5/8 X 24 Thread Pitch Includes: 5/8in Muzzle Device Alignment Kit Weight: 1.4oz Package Contents: Spikes Tactical R2 Brake - H.V.S. Spikes Tactical SBV1067: R2 - HVS Brake 5.56 - Melonite