All devices come standard with a free steel crush washer.
Specs: 5.56 1/2×28
MilSpec 416 Stainless, from a local supplier
.468″ Thru hole, to fit a large variety of calibers.
3 x .125″ Comp holes, for vertical recoil reduction.
6 x .25″ Brake ports, terminating slightly below the device’s center-line to prevent prone dust up and maximize recoil reduction.