... USB /SD Jack, can read and play song.5.Digital microphone input6.Digital MP3 input7.Built-in 5.5Ah battery 8.Music ... +3“*1Resistence8 OHMMeterialWood/metalConnectorWith 5.5Ah battery , USB / SD card reader ,digitalMP3 inputCompetible format dvd,svcd,MP3,MP4,WMA,VCD,DVCD ... Selling 15inch 90W Black Portable PA system with USB,SD reader,Mics