The Dead Air Shim Kit for barrels with 1/2-28 threads is composed of three different shim thicknesses. The graphic on the packaging details the thicknesses and identifying features of the shims included with the kit. Always place the thickest shim(s) on the barrel first.
Dead Air DA001 Shim Kit1/2″-28 tpi 3 Different Shim Thicknesses Included (.004″, .006″, .060″)