Check the listing for details. 5.56 Linear Compensator Muzzle Brake Steel 1/2-28 USA Made For Bolt Action Rifle. Color: Black, Condition: New. Listed at 24.88 USD. Linear Compensator Sound Forwarder Muzzle Brake 1/2-28 TPI, Fluted, Steel With Nitride Finish This 6 ported sleek linear compensator redirects sound and concussion away from the shooter and down range. This device is particularly useful for hunting/range shooting where blast is desired to be directed downrange. Attractive fluting on the brake reduces weight, and creates a lower profile and a clean look. A crush washer is included. 100% USA Made of top quality steel. Overall Length: 2.26 inOuter Diameter: 0.87 in.Net Weight: 3.7 oz.Material: SteelCrush Washer IncludedUSA madeThread Pitch: 1/2-28 TPIFinish: NitrideWorks With Any Action Type* Please note that the manufacturer, Tacfire Inc., sells this same comp for both the 5.56 and 9mm cartridges. The exit hole is bored out to accommodate 9mm, but it does not affect performance when used on a 5.56 due to the nature of how a linear compensator works *This part can be used with bolt-action rifles