This gemstone testing equipment is not only a diamond tester, but also a multi gemstone tester. It can detect if a gemstone is real or , including: diamond, sapphire, ruby, crystal, agate, jadeite, and other precious stone of various sizes. If the number of lights equals or exceeds 9, and it beeps, it means the diamond is true. * If the lights is about 9 and it beeps, it means the sapphire is true. * If the number is 6.5-7, it means the agate is true. * If the number is 7-8 , it means the crystal is true. * If the number is 6-7, it means the jade is true. Before Test: 1. Put the battery in the tester. 2. Take off the probe cap. 3. Turn on the switch. 4. Make only one light light up on the scale. 5. Make the " lamp" light on. 6. (If test diamond, you then need to turn on the lights number corresponding to the indoor temperature and diamond weight.). 7. (If test other gems, you'd better calibrate the probe, : by placing the probe vertically on a glass, then adjusting the light to 5, then test the gems.) supply: 9V Battery (The product is shipped without battery) Uses: / small switches for testing diamonds Colour:Black Material:PC + metal Size:16 x 4 x 2cm Package Contents: 1 * Diamond Selector 1 * Testing Platform 1 * Carrying Case 1 * User Manual 1 * packing box NOTICE: No matter what gemstone you are testing, the probe needle and the tested object must be at a 90 degree angle. When testing diamond, your right index finger must keep touching the metal panel on the back of the tester, while you do not Press the panel if you test other gemstones. Do Not test any metal. Do Not wear glove. 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.