The Presidium Multi-Tester utilizes the combined principles of thermal and electrical conductivity from Presidium's patented technology. The measuring probes together with the electronics circuitries are designed to pick up and segregate data collected from the stones via a customized micro-controller. Within a split second, the test result will be displayed. Features: Surface mount technology. Retractable tip to ensure the accuracy and consistent pressure between the measuring probe and gemstone. No waiting time between tests. Clear LED display for diamond, moissanite, stimulants and metal. Built-in metal detector. Low battery indicator. Automatic power down.