... MP3 play. SpecificationsGuitar Mini Speaker1. Guitar Mini Speaker With TF Slot 2. Stereo sound quality, bass, alto,. High sound ... green led is lit on the top left, enter TF card reading, reading U-disk status. Green led ... switch to AUX mode, you cannot use the read TF card reader U-disk function.4. The previous ... up and down buttons in the Flash disk and TF card to play mode, short press to next song ...