This is a Thunder Beast Arms Corp SR Muzzle Brake 338. It features a 5/8x24 thread pitch for .338 caliber with Ionbond DLC finish. This brake is designed for the 338 Ultra SR and Dominus SR suppressors. It attaches and detaches easily with a quick release mount, and provides a second layer of retention as both the brake and suppressor will be threaded to each other. Besides being the necessary mount for the SR suppressors, the TBAC SR brake also provides an industry standard brake, reducing recoil without adding much length. Peel washer included. Buy online today!