Technical Features: 1. The diamond tester is an electronic instrument designed and manufactured according to the thermal conductivity of diamonds to identify the true and false diamonds. It can also be used for testing sapphire, ruby, crystal, agate and other stones. 2. This diamond tester pen is a precision electronic instrument, the use environment is 5-35 ?, and the relative humidity of air is below 80%. 3. The tested gemstone must be clean, dry and at room temperature.Steps for Testing: 1. Turn on the power, the power indicator is on, the instrument starts to warm up, and the instrument can be used in a few seconds. (After the lamp on ready ok ). 2. Put the measured bare drill into the appropriate concave hole of the support tray, and put its table top up. The inlaid ones need not be placed in the tray hole, but can be held by hand. 3. Choose a number in the calibration table according to the temperature and the size of the stone to be tested (for masonry, it is recommended to use 4 as the calibration number. For other gems, please refer to the hardness of the gemstone). 4. Find the selected calibration number under the light bar, and turn the switch toward the direction of ON to let the light bar reach the place the selected number lies. 5. Start to test diamond or other stones, your hand needs to hold silver triangle conductive plate when testing and the probe tip needs to perpendicular to the tested stone. 6. If the number of lights equals or exceeds 9, and it beeps, it means the diamond is true.Specification: Material: Plastic Working power: DC9V battery (not included) Size: 160mm * 40mm * 22mm/6.30" * 1.57" * 0.87" Weight: About 130g/ 0.29 Lb