Features: 1.The thermal conductivity meter is based on the thermal conductivity of diamonds designed and manufactured, specifically for the identification of genuine and false diamonds an electronic instrument. 2. The instrument for precision electronic equipment, the use of the environment for the 5-35 degrees Celsius, air relative humidity at 80%. 3. The gemstones to be tested must be clean, dry and at room temperature. 4. Pocket portable handheld. 5. Non-destructive testing, simple and accurate. 6. Instructions: 7. Open the thermal conductivity meter power supply, the probe heating, generally takes 20 seconds. 8. The hot needle touches the sample surface, according to the thermal conductivity of the instrument can determine whether the signal is diamonds tested samples. specification:Working power: DC9V battery (not included) Weight:165g Overall dimensions: 160*40*22mm PackageList:1 x Diamond selector II tester 1 x 60 times magnifying glass 1 x Protected leather bag 1 x Texting Platform 1 x User manual Note*DIAMONDS 1. Beeping sound (beep-beep-beep) 2.（1）1~4 of the Red Lamp box OF the Level Meter，（2）will light on. (More no. of Red Lamp boxes will light up for bigger sized stones.) *DIAMOND SIMULANTS(Except Synthetic Moissanite) 1. No Beeping sound. 2. No Red Lamp boxes will light on. Green and/or up-to Yellow Lamp boxes may light on depending on the type of stimulants.) *METAL ALERT 1. Continuous buzzing sound. (The thermal conductivity of the metal is very high and can give the same indication as a Diamond with most Thermal Probes. The Diamond Selector II has a Metal Alert buzzer to warn you when the Probe tip touches metal.) If you hear the Metal Alert buzzing sound. re-touch the Probe tip so as to touch only the tested stone.