0.56inch 3 wires LED Mini Digital Voltmeter DC 0V To 99.9V Red/Green/Blue Measuring range: DC 0 - 100 V You can install these mini voltage display. Precision: 1% Input range power supply: DC 4.5 - 30V Measuring range: DC 0 - 100 V You can install these mini voltage display. Precision: 1% Input range power supply: DC 4.5 - 30V Display: Three digits Working current: less than 20mA Display color: red Storage Temperature: -10 ~ + 65 Black connects the negative pole common, red to the positive terminal of the power supply, white with positive polarity. Sample voltage 1 x voltmeter Note:Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/-1-3cm.