1.2. Supports Typec power interface DC5V power supply or button battery power supply. The battery installation port has a hole on the side for easy removal of the battery. 2.3. This kit can perform mathematical calculations of addition, subtraction, multiplication and division, and also convert color ring resistor values. It is a multifunctional product suitable for electronics enthusiasts to practice welding and learn to use. 3.1. Composed of special circuit boards, digital tubes, microcontrollers, buttons and other components; with stable product performance and long service life. 4.4. The digital tube display calculator production kit can realize mathematical calculations of addition, subtraction, multiplication and division, and can also convert the resistance value of the color ring resistor. Suitable for welding practice, electronic training, experiments and other purposes, very suitable for DIY enthusiasts.