Complete shim kit allows you to properly index your muzzle device to your barrel. The kit comes with seven different thicknesses of stainless steel shims. The shims can be used alone or in different combinations to give you the desired thickness needed to correctly index the muzzle device to the barrel. Includes the following shims .002" (2), .003" (2), .004" (2), .008" (2), .010" (1), .015" (1), and .030" (1).