Product Description Power supply: DC9V battery (battery not included) Diamond measuring pen: There are 2 shades, 3 shades of light display, easy to distinguish real and fake diamonds, easy to operate Material: plastic Working method: 1. Turn on the power, the power indicator lights up, The instrument starts to warm up and is ready to use after a few seconds. 2. Insert the bare drill bit to be tested into the corresponding hole of the bearing frame with the tabletop facing up. The mounted one does not need to be placed in the slot, it can be held by hand. 3. Light up several LEDs according to the weight of the real and fake diamonds and the temperature of the measuring part. 4. Remove the probe cover, hold the instrument and touch the conductive plate on the back cover of the instrument with your right index finger. Lightly touch the probe perpendicularly to the table of the real and fake diamonds to be tested. 5. Note the instrument's reflections. If the remaining yellow LED lights are on and there is a 9-second tube buzzing, the tester is a real diamond. On the other hand, if less than 9 lights are on and the instrument does not emit a high-frequency beep, it is a fake diamond or product. Package contents: 1 * Warm tips Drill pen 1. The thermal conductivity meter is an electronic instrument specially designed and manufactured according to the thermal conductivity of diamonds to identify the authenticity of diamonds. 2. This instrument is an electronic instrument, the working environment is 5-35 degrees Celsius and the relative humidity is below 80%. 3. The gemstone to be tested should be clean, dry and at room temperature. 4. When testing, it is generally sufficient to adjust to one grid or two grids.