For scope base adjustment, sight adjustment, head-space adjustment and checking, restoration of misaligned parts soldering on for buildup, inletting templates, spacers. You name it, and somewhere along the line a shim can be used for everything from shimming, to measuring, to fixing! KIT No. AF-12 consists of one piece, each, steel shim stock, 6" x 12" in the following thicknesses: .001", .0015", .002", .003", .004", .005", .006", .007", .008", .010", .012", .015".