2 types of display mode available Time display only TimeDateTemperature rotation display Calendar Alarm Temperature or Range 16122 1224H time mode 3 levels bright HighMediumLowOff Automatic brightness control function using the light sensor is a mode in which the LED is set to the low brightness in the dark space without light and the LED is automatically changed to the high brightness in the bright space Please note that this item is powered by adapter only The builtin CR2032 battery is for time memory feature only and is not a power source The item is powered by adapter only and comes with a EU 220V to US 110V outlet plug adapter Please remove the protective film on the back of the clock before use