[Simple and fast] 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 simulated gems. [Easy to use] Diamond tester is easy to use, with LED lights and audio alerts. Just place the tip of the diamond tester gently on the gemstone. If the gemstone tested is a diamond, the pen will beep and display a row of fully lit LED lights. If the gem is crystal or zirconia, the tester will not beep. [Easy to carry] Diamond detector and 60X LED loupe are both lightweight and come with a carrying bag. They can be placed in your wallet or backpack without taking up much space. They are a must-have kit when going to a garage sale, market, swap meet, etc. [Magnification] The package also contains a 60X LED loupe. It can help determine the details of diamonds and can also be used for coins, reading, inspection, and other close-up viewing tasks. [Wide range of use] Jewelry diamond testers have a wide range of uses, not only for testing diamonds but also for applications in industry, circuit boards, printing, gardening, identification, education, geography, homes, and offices. Color: Black Material: Metal Package Contents: 1 set x Diamond Tester Only the above package content is included; other products are not included. Note: Light and different displays may cause the color of the item to appear slightly different from the real thing. The measurement allowed error is +/- 1-3 cm.