Product Features:1. Pocket portable handheld. 2. Non-destructive, easy and accurate operation. 3. Operating power: DC 9V battery. 4. External dimensions: 162 x 42 x 22 mm Weight: approx. 160gOperation method.1Turn on the power, the power indicator lights up and the instrument starts to warm up, after a few seconds the instrument is ready for use. 2Place the bare diamond to be measured into the suitable concave hole of the support tray and place it with the table side facing upwards. Those that have been set do not need to be placed in the tray hole, but can be held in the hand. 3. Dim a number of light emitting diodes according to the weight of the real or fake diamond to be measured and the temperature of the measurement site. 4, remove the probe sheath, hold the instrument, the right index finger touch the instrument back cover conductive plate; make the probe vertically with the measured real or fake diamond table surface gently contact. 5, carefully watch the reflection of the instrument, if the remaining yellow light-emitting diodes lit, when lit up to 9 diodes, and accompanied by a beeping sound this means that the person being measured is the real diamond. In contrast, if less than 9 are lit, and the instrument does not emit a sharp beep, it means that the diamond is a fake or counterfeit.Repair and maintenance:1. The probe of the instrument is very sensitive and must be protected with special care. 2When the ready indicator is very dark, it means that the battery will be exhausted, you should replace the battery in time. 3If the instrument is not used for a long time, please remove the battery. 4For accurate detection, it is recommended to calibrate the instrument once a year.Complete set includes: 1 x Diamond Testernot included the battery, 1 x English Instruction Manual.