DROK Fahrenheit &deg;F Panel Thermometer DC 12V Voltmeter Temp/volt Gauge Green LED Digital Electronic Clock 18B20 Probe Time/Voltage/temperature 3 in 1 digital meter of four operating modes Waterproof dc18b20 sensor probe measuring -67f to 257f and with high accuracy of about 0 2 C 12-Hour time meter with power-off memory function and its battery is available for 3 to 4 years Adopts SMD technique; its digit would NOT shake; 4-digit LED display Has reversed-connection protection, meaning the meter will NOT burn when being connected reversely