... Support USB Disk /SD Card and 3.5 aux in Building in high quality MP3/WMA ... decoder Building in Amplifier chips Widely extend external audio sources, like PC, MD, PSP, GPS ... Blaupunkt.. Free accessores:usb extend cable, 3.5 line audio cable,usb reader,user manual: Installation Guide: ... etc.Press “Repeat” button to switch between MP3 and Aux in.Install illustration: car audio usb interface CE,FCC,RoHS ...