High Precision Diamond Tester Professional Jeweler (black Diamond Tester)Features:[Fast Safe] Professional Diamond Selection II will show real diamonds or fakes. Designed for fast, precise and safe diamond testing.[Intuitive Design]: LCD display and LED indicator. Test diamonds with a big/small switch, which emits an audible sound to easily distinguish readings.[Easy to use]: The diamond test pen is easy to operate and get results without a professional. Just turn on our diamond test pen detector; place the tip of the diamond tester on the gemstone (a gentle pressure is enough), the tester will not beep if the gemstone is fake, crystal or cubic zirconia .[SET INCLUDED]: The diamond tester is battery powered for easy use. Requires 1 standard 9V battery.