SMAKN&reg; RED 12/24V 0.36" 3.0~30V Small Digital DC Panel Mount Voltmeter Car Battery Voltage LED Tester Red 2 Wires Measure Voltage: DC 3.0~30V (No Need power supply) Measurement Accuracy: 1% (+/- 2 digit) Display: Three 0.36" digital LED Tube Display color: Red Operating Temperature: -10c ~ 65c