Features: Made of high quality material, strong, and good performance, long service . High accuracy and quick response, it is speical designed to quickly distinguish natural diamonds from various diamonds. The principle is based on the different thermal conductivity of diamonds and various imitation diamonds. 2 kinds of sound, 3 kinds of color lights, easy to identify the authenticity of the . Non-destructive testing, easy and accurate operation. Pocket, handheld type, easy to use. Working power supply: DC9V battery (battery not included), Weight: 0.15873282864 pounds, Manufacturer: Wesafrae