Usage Tips:[Simple and fast]Our 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 instructions. 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 lighted loupe are both light and handy, and both are equipped with a carrying bag. They can be easily put in your wallet or backpack without taking up a lot of space. They are a must-have kit when you are going to a garage sale, market, swap meet, etc. [Magnification]The package also contains a 60X LED lighted loupe . It can determine the clarity of diamonds, and can also be used for coins, stamps, reading, inspection, etc. [Wide range of use]Jewelry diamond testers has a wide range of uses, not only for testing diamonds, but also for industry, circuit boards and printing, gardening, identification, education, geography, homes and office colour: black Material: Metal Package Contents: 1 set x Diamond Tester Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.