Docooler Multi-Function Digital 12V Car Voltage Alarm Temperature Thermometer Clock LCD Monitor Battery Meter Detector Display (Blue) Date/Hour, Week/Second Display. Switch the display between 12-hour and 24-hour Alarm Clock. Snooze function with 5 minutes interval.Switch Temperat Measure temperature, measurement range: -50C-70C Sampling period of thermometer? 20 seconds. Car battery voltage indicator. LED backlight with double colors optional? LED backlight is on and lcd show all with automotive power. No backlight, and LCD screen only show time with spare battery power (not included)