1. Start button. .
Press it briefly to exit the menu you are in or to pause/resume the sport you are doing.
2. Charging connector.
Bring the end of the magnetised charging cable towards to this connector so that it connects to the watch. Plug the USB end into a USB charging port to charge your device.
3. Heart rate monitor and oximeter.
These sensors must be placed close to your wrist to be able to take the measurement correctly.