By pressing the sos button, the device will send a message to all mobile phones that have installed the application and will also send an SMS to a phone number. Then the device will automatically start calling up to three phone numbers that you have registered on the device as emergency numbers. If the first number does not answer, it will call the second, and if the second does not answer either, it will call the third phone number. This process will be repeated twice. Once the call is answered, you will be able to talk to them on speakerphone.