NOTE from Manufacturer:

Our 1/2x28 muzzle brake mounts are intentionally bored out to .30 cal. This design choice gives the device greater versatility since it can safely be used across multiple calibers, not just 5.56. The slightly larger bore will not cause baffle strikes or alignment issues, and any performance difference (in terms of flash suppression or muzzle control) compared to a caliber-specific 5.56 device is negligible.

Available for standard 5.56×45 threaded barrels, the Keymount Muzzle Brake is your gateway to silence. When you're ready for peace and quiet use the Keymount brake to quickly attach your Sandman-L, Sandman-S, Sandman-K to your rifle. If you're not quite ready to turn up the silence, you can still employ the finest brake on the market and experience a flatter shooting rifle with minimal concussion compared to traditional muzzle brakes.

Features:
1/2X28 thread pitch
2.6" length