1. The diamond tester pen is designed for fast, accurate and safe diamond testing. In just a few seconds, even a novice can immediately distinguish real diamonds from other imitation gemstones. 2. The diamond tester is easy to use, with LED lights and audio instructions. Just gently place the tip of the diamond tester on the gemstone. If the gemstone being tested is a diamond, the pen will beep and show a row of fully illuminated LED lights. If the gemstone is crystal or zircon, the tester will not beep. 3. The diamond detector and 60X LED magnifier are lightweight and both come with a carrying bag. They can be put in a purse or backpack without taking up much space. They are a must-have when you go to the garage, market, barter, etc. 4. The package also includes a 60x LED magnifier. It can identify the type of diamond, and can also be used for coins, reading, checking, etc. 5. Jewelry diamond testers are widely used in non-diamond testing, as well as in industry, circuit boards and printing, gardening, identification, education, geography, home and office. 6. color: black 7. material: metal 8. package contents: 1 set x Diamond Tester 9. only the above package contents, other products are not included. 10. Note: Due to the light and different displays, the color of the item may be slightly different from the actual item. The measurement allowed error is +/- 1-3cm.