Jewelers, watchmakers, and gemologists use measuring tools to document, communicate and design. Widely used in so many trades, these gauges are precision set and ideal for measuring small parts and designs. Many of the gauges and calipers can measure the inside diameter as well as the outside diameter using caliper arms that will reach into small areas. Because of their versatility, these gauges are a great addition to any workbench: they can measure gemstones, setting sizes, ring sizes, millimeter size, and so much more.