... mp3 decoder boardSingle Spectrum with balance display, SD Card, USB, FM RadioFeature & function: Single Spectrum with balance display, support USB/SD ... :last/next song,volume,play/pause,mode Product No.502Q-A Features Shape Oblong Shell ABS Color Sliver & black Control ... R&D StaffProduct Line: mini Card& USB reader speaker, portable FM radio speaker, mobile speaker, active speaker, tower speaker, stage ...