Function: 1Play Mp3 Format Music From Sd Card Or Usb Storage Devise. 2Connect 3.5 Stereo Audio Cable To The "Audio In" Socket And Play Music From Mp3/Mp4/Mpg, Mobile, Computer, And Other Audio Equipment. 3 A Remote Control Is Supplied With The Unit. 4Buildin High Capacity Battery That Can Play 3 To 5 Hours.