Drok Led Voltage Fahrenheit Temperature Time Digital Multimeter Dc 030V 12V/24V Voltmeter Thermometer Clock 3In1 Multi Meter Gauge Panel Four display modes: time only; temperature only; Voltage only; time, temperature, Voltage Alternate display Waterproof dc18b20 12-hour time system with memory store function when power off and its battery is available for 3 to 4 years Adopts waterproof ds18b20 sensor probe, wide temperature measuring range(-67 to 257) Wide Voltage measuring range(dc 0-200v) and power supply (dc7-30v), high accuracy(+/-0 1V) Has reversed-connection protection, meaning the meter will NOT burn when being connected reversely