Automotive Modified Voltmeter Micro-Transparent Waterproof Voltmeter 0-100V

Digital Voltage MeterDC0-100V   IP67
Features
Compact size
Digital LED display (3 digits)
Self-powered from the measuring DC voltage
Floating decimal point for better resolution below 10V
Completely sealed design (IP67)
Reversed polarity input protection                                                              
 Specification
Product display: LED display
Measure  voltage range  | DC 0-100V
powering  voltage  range |DC 4-30v
Current Consumption | <30mA
Sampling Rate | 5 readings/s
Resolution | 0.01V (input <10V) / 0.1V (input >10V)
Product features: Fully sealed design (IP67) Small size Digital LED display screen Input protection
Wiring:Red line to 4-30V power supply /

The yellow wire connection requires the positive pole of the measuring device (0-100V) (note that you cannot connect the same device with the red wire)

Black wire ground