Universal pcb Board -SD/USB,FM radio,LED -power on/off,last/next songs, volume, Pla/pau,repeat -DC5.0V IN ... radio and digital screen display, with power on/off switch, remote control, and so on.Key function:power on/off,last/next songs, volume, Pla/pau ... Car audio, multimedia speaker, subwoofer, amplifier, electronic products and so on.-Key function: last songs, next songs, volume control, Play/pause ...