The Tiger Rock Muzzle Brake Jam Nut is designed to fit correctly every time you install your muzzle device. This steel jam nut is 5/8in x 24 threaded, just like a standard AR-10 muzzle brake, so it can be installed and removed easily unlike many other muzzle brake threaded muzzle devices. The design of the Tiger Rock Muzzle Brake Jam Nut ensures that the brake is always perfectly aligned, giving you a great deal of accuracy. Compatible with most muzzle brake accessories. Package contents: Tiger Rock AR-10 .308 Steel 5/8inx24 Threaded Muzzle Brake Jam Nut.