Mini Digital Voltmeter DC 4V-30V 0.28 Inch Two-Wire Mini Digital Voltmeter Voltage Tester Meter 3 Colors (Green)

Specification: Operating Voltage: 4.0-30V Detecting Voltage: 0-30V Working Current: <20 mA Detection Rate: ? 200 mS/Times Install the hole: 23 * 10 mm Measurement Accuracy: 3 % Working temperature:-10 ~ +65 ? Working humidity: 10~80% (No condensation) Dimensions: 22.5 * 10 * 7 mm Measurement rate: ge; 200mS / times Working pressure: 80~106kpa Wiring:Red wire: Power supply +        Black wire:Power supply -, Measured Voltage -        White wire: Measured Voltage