These suppressor thread adapters allow you to convert AK-47 style threaded muzzles to receive 5/8x24 or 1/2x28 threaded accessories. These surplus rifle threads require a muzzle face index for perpendicularity, making them incompatible with muzzle devices that require timing. The use of these adapters converts these threads to conventional threads with thread shoulders, allowing common muzzle devices to be mounted with timing shims. Provided 3/4" wrench flats permit proper installation torque to be achieved.