Gage sets in this class have tighter thickness tolerances and superior workmanship than typical feeler gage sets. Size markings are larger, clearer, and easier to read than any other gage set on the market. XF SERIES gage sets are chosen by professionals worldwide. The fan style case is made from a heavy gauge stainless steel designed to resist the elements. Each XF SERIES gage set comes packaged in a reusable, tough polypropylene case for long lasting protection. All thicknesses are clearly marked on the packaging to save time. Proudly made in the USA.