Pcb with LED display -support SD / USB Card Reader,FM radio,LED display -MP3 decoder,pcb assembly -DC 5.0V,IN -power ... on/off Pcb with LED display(Mini audio board) Function and features:MP3/SD/USB ... -Application: Ordinary audio combination, Car audio, multimedia speaker, subwoofer, amplifier, electronic products and so on.-Key function: last songs, next songs ...