DC 12V Battery Meter Battery Capacity Voltage Monitor Gauge Indicator DC 24V 36V
Simple wiring, you just need to connect the red wire to positive and black one to negative. ✹✹ Easy to read: Our battery monitor can be set auto off after 10 seconds or always display either % or Vdc.
Digital AC Voltage Frequency Meter, AC 80-500V Voltmeter 45-65Hz Frequency Count
Working frequency: 45-65 Hz. ” Clear and bright LED digital display, much better than LCD.