Remove the cap from the testing pen 》 Insert the battery we attached 》 Turn on the diamond tester pen and wait until both the lambs OK 》 Place the pointer vertically on the of the stone 》 Observe the indicator lights and listen to the sound 》 get the result For testing diamond(include real diamond and Moissanite), it emits beeping-beeping-beeping in a low frequency, 1 time/second. Meanwhile lights ≥ 9 (Notice: the bigger the stone is, the more lights on) Place the tip of the diamond tester gently on the gemstone. If the diamond is fake, crystalline or cubic zirconia, the tester not beep. An excellent diamond tester tool kit, suitable for handling any exposed or mounted diamonds and gems. Popular among professionals, hobbyists, coin enthusiasts, and business owners alike. Excellent tools. Excellent Value. Great gift idea. Our gemstone tester has an intuitive design, light and portable, and the jewelry diamond tester is equipped with LED lights and audio instructions. As long as the tip is perpendicular to the test masonry and the switch is pressed, the result can be obtained. We have to choose the diamond size before using the diamond tester.Otherwise we may get the incorrect result. Color: As Shown Material: Metal Package Contents: 1 set * 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.