1、Small size, easy to carry and store, wide measuring voltage range, efficient and convenient. 2、12‑bit AD microcontroller with high measurement accuracy, and strong anti‑interference. 3、Composed of professional PCB materials, stable performance and long service life. 4、The working voltage is DC12V, the measuring range is DC0-55V, and the relay life is 100,000 times 5、With strict quality control and quality assurance, high safety factor, can be used with peace of mind. Material: PCB Measuring Range: DC0-55V Relay Life: 100,000 times Measurement Accuracy: 12-bit AD chip Interface Description: Input Terminal: VCC: Positive power supply GND: Negative power supply Output: NC: NC terminal COM: COM terminal NO: NO terminal Key Description: K1: Short press to adjust, long press for 2 seconds to turn on/off display K2: Short press to adjust the time selected position plus 1 long press for 0.5 seconds, display mode +1 1. Press the first "K1" digital tube hundred digits to flash, adjust the lower limit hundreds digit, press "K2" 0-9 to change and adjust 2. After adjusting the hundred digit, press the second "K1" digital tube ten digits to flash, the lower limit tens digit is adjusted, press "K2" 0-9 to change and adjust 3. After adjusting the tens digit, press the third "K1" digital tube to blink, and adjust the lower limit ones digit, press "K2" 0-9 to change and adjust 4. After adjusting the units digit, press the 4th "K1" digital tube to blink the hundred digit, and adjust the upper limit hundreds digit, press "K2" 0-9 to change and adjust 5. After adjusting the hundred digit, press the 5h "K1" digital tube tens digit to flash, adjust the upper limit tens digit, press "K2" 0-9 to change and adjust 6. After adjusting the tens digit, press the 6th "K1" digital tube to blink, and adjust the upper limit ones digit, press "K2" 0-9 to change and adjust During the above adjustment process, if no key is pressed for adjustment within 2 seconds, it will automatically jumping back to the initial interface, and the setting data will be saved 1 x DC Voltage Detection Module