•  TF card playback
•  U disk playback and intelligent mobile charging
•  AUX and audio antenna
•  Battery charging DC-5V
•  Indicator light display
•  ON/OFF
•  Short press is play/pause in MP3/BT long press.
•  (-) Long press: reduce volume. Short press: In MP3 mode is previous song.
•  (+) Long press: Increase volume. Short press: in MP3 mode is next song.
•  (M) Short press: BT/USB/TF/AUX modes switch