Power key: To power off M4 B3, press and hold power
key for a few seconds, then tap the options to confirm.
When M4 B3 is on, press the power key once to
activate or deactivate the screen.
Home key ( ): Touch the key to return to the home
screen. In idle screen, touch and hold the key recently
Menu key ( ): In idle screen, touch the key to view
recently accessed features.
Back key ( ): Touch to go back to the previous menu.
