K&B Stone and Diamond Measuring Gauge

A small, pocket-sized gauge constructed from aluminum. Ideal for measuring diamonds, loose gemstones, and settings from .03 to 4 carats. It also provides the corresponding millimeter values, ranging from 2 to 11 mm. To use, simply drop stones through the holes to measure their size, and an inner revolving gauge will measure settings. The gauge is tempered for durability. A birthstone chart is embossed on the opposite side.