There are 3 buttons in the middle of the device, from left to right,
"+"button, "power/setting" button,"-" button;
5.1 ON/OFF device
ON: Long press"power/setting" button for 3 seconds, Display
all lights up;
OFF:Long press"power/setting" button for 3 seconds, Display
lights:OFF
Temperature unit °C / °F Switch Mode:
Both press + and - button for 3 seconds, display lights up F1,
select + for °C or - for °F, press power button to save the setting.
Mute Function
Both press "+" and "-" for 3 seconds, and the screen will display F1 ,
Press the Power button 3times to enter F4, and then press - for
mute function or "+" back to alarm on