[Perfect for Novices and Professionals - Easy-to-Use Diamond Tester] This diamond tester is designed for both beginners and professionals. Simply power on, the tip against the gemstone and wait for a beep to know if it's a real or fake diamond. A real diamond lights up to 9 and emits an audible sound. No reaction means it's a fake or simulant like cubic zirconia (). Get quick, accurate results every time [Thermal Conductivity for Accurate Testing - Diamonds Moissanite & Gemstone Tester] Our tester uses thermal conductivity to accurately distinguish real diamonds, moissanite, and other fake gemstones. Real diamonds and moissanite have distinct thermal properties, and the tester's probe produce a high-frequency sound to confirm authenticity. This ensures reliable gemstone testing and avoids false positives when testing synthetic diamonds or other stimulants [Adjustable for Carat Sizes - Easy to Test Small & Large Diamonds] Adjust the tester's settings according to size displayed on the screen. For diamonds over 1.0 carats, turn on one green light; for 0.5 carats, two lights; and smaller stones, three to four lights. This feature ensures accurate results without needing to know the exact carat weight [High-Frequency Sound for Metals & Simulants - Accurate Testing Feedback] When testing metals or simulants, the device emits a high-frequency sound due to the thermal conductivity similarity to diamonds. proper testing procedure and avoid testing on metal, skin, or water for accurate results [Complete Testing Kit] The kit includes 1 diamond tester pen, 1 USB cable, 1 testing platform, 1 user manual. This gemstone tester kit is ideal for home jewelers, diamond enthusiasts, and professionals, making testing diamonds, moissanite, and other gemstones easy and reliable Color: Black Material: Plastic Package Contents: 1Pcs * diamond tester Only the above package content, other products are not included. Note: Light reflection 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.