Product Features: 1. Pocket portable handheld design. 2. Non-destructive, easy and accurate operation. 3. Operating power: DC 9V battery. 4. External dimensions: 162 x 42 x 22 mm. Weight: approx. 160g. Operation method: 1. Turn 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. 2. Place the bare diamond to be measured into the suitable concave hole of the support tray with the table side facing upwards. For set stones, placement in the tray is not necessary; the instrument can be used while holding the item in hand. 3. A number of light-emitting diodes will illuminate based on the characteristics of the diamond being tested. 4. Remove the probe sheath, hold the instrument, and place the right index finger on the conductive plate on the back cover. Gently make vertical contact between the probe and the table surface of the diamond being tested. 5. Observe the instrument display. If nine light-emitting diodes illuminate and a beep sound occurs, the tested stone is a real diamond. If fewer than nine diodes light up and no beep sound is emitted, the stone is not a natural diamond. Repair and maintenance: 1. The probe is highly sensitive and must be handled with care. 2. When the ready indicator is dim, the battery is low and should be replaced promptly. 3. If the instrument is not used for an extended period, remove the battery. 4. For optimal accuracy, it is recommended to calibrate the instrument annually. Complete set includes: 1 x Diamond Tester (battery not included), 1 x English Instruction Manual.