1. Operating voltage: no need to connect to any power supply, two-wire system - 2. The two-wire voltage meter design, the wiring is simple, easy to install - 3. When there is a slight error, you can calibrate it through the circuit board, "fine-tuning" potentiometer for calibration
Specifications of AC 70V-500V 0.56" LED Digital Voltmeter Voltage Display 2 Wires 0.56 inch Voltage Meters Electrical Instruments 3 B