Feature:1.Easy to use even for a new beginner2.Emit audible sounds to give accurate reading3.Diamond indicator will be showed if the stone is a REAL diamond (Green light)4.Metal alert (continuous buzzing sound when user accidentally touches metal rather than stone )5.Large / Small switch for testing diamonds +/ - 8 points6.To emit sounds to give accurate reading7.LCD display & LED indicator8.If a stone is Fake crystal, a simulant such as cubic zirconium ( CZ ), will be no reaction.Item type: Diamond TesterMaterial: Metal, PlasticColor: Black (shown as the pictures)Size: 135*40*23mm.Power By: 1*9V battery(not included).Operating methods:1. Open the power, the power indicator light, instrument began preheating, after a few seconds instrument can be used.2. Take the naked drill to be tested into support tray appropriate sunken hole, and its mesa upwards. Those already inlay need not put tray hole in, you can use hand to hold it.3. According to the weight of the tested diamonds and measuring the temperature place to move several bright leds.4. Take down needle sheath, handhold instruments, the right index finger touch the conductive plate on the back cover of instrument. To make the probe vertically and gently contact with mesa of measured diamond. 5. Carefully watching the instrument, if the rest of the emitting diode light reflect yellow, when light place moves to nine diodes with accompany beeping, this explains those tested are for real diamonds. On the contrary, if light place moves to insufficient nine diodes, and without accompany beeping, this explains fake diamond or counterfeit.Package include:1 * Diamond tester.