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Functions:
* Time and calendar display
* Alarm and snooze
* Indoor temperature (range: 0℃～+50℃) and humidity (range: 10% ~ 99%) display 
* Indoor temperature and humidity trend display
* RF outdoor temperature (range: -40℃～+70℃) and humidity display function
* RF outdoor temperature and humidity trend display
* Temperature tolerance: ±1℃
* Humidity tolerance: range 40% ～ 80%: ±5%, otherwise ±8%
* Displays MAX/MIN values of temperature and humidity
* Record and alert function of outdoor rainfall
* Backlight function