DROK -10~80  Cigarette Lighter Plug Digital Voltmeter Temperature Gauge 2 in 1 12v/24v Car Car Battery Monitoring Voltage Temp Meter Red Blue Dual Display Display color: Red+Blue Power mode: cigarette lighter power Input voltage: 12V and 24V Universal Function 1: Car battery voltage monitoring Function 2: Car Temperature measurement (-10 ~ 80 c)