Mode switch single press to switch modes
Next song/Volume+:At the USB/T card mode, short press to play the next music long press to increase the volume
Previous song/Volume-: At teh USB TF card mode, short press to Play the prious music long press to decrease the Play/Pause:
(I At the card mode,single press to enter play/ pause function
(3) At the TF crad mode,single press to enter play/pause function