1.alto-falante 2. with USB charge 3. with mp3 player Main function and features for alto-falante 1, Support SD ... and USB disk, automatically read the first audio device you insert2, With AUX IN, it can compatible with MP3, MP4, CD player and ... and USB disk, automatically read the first audio device you insert2, With AUX IN, it can compatible with MP3, MP4, CD player and ...