theelectronicgoldmine.com/pro...
Small 3 digit DC voltmeter has 3 leads and measures 0-100V from a green 3 digit display. To use, simply provide 4VDC up to 40VDC on the red and black leads to provide powering voltage to the voltmeter. Use the yellow(+) and black (-) lead to measure any voltage in the range of 0 to 100VDC. Accuracy ±1%, requires less than 30mA. Display height 0.36", and overall size is 0.9" long x 0.55" wide x 0.32" depth (not including mounting ears).