Discover the Sylvan Arms muzzle devices that come in 5/8 x 24 or 1/2 x 28. Made out of 17-4 SS for durability and long life. They are designed to work with the Sylvan Arms 30 Cal and 223/556 suppressor lines. The 5/8 x 24 fits our 30 cal can while the 1/2 x 28 fits our 223/556 can. The muzzle device can also be used as a Flash Hider. Easy to install, simply screw the Flash Hider onto your appropriate size barrel and tighten with an armorer wrench, No washer is needed. Designed and Manufactured in the USA, in Myrtle Beach SC.