Direct Connection via CD changer Port with CD quality sound.Control music files from your car radio panel or steering wheel.Support USB Flash, SD Card and 3.5mm jack input.Building in high quality MP3/WMA decoder.Building in Amplifier chips.No signal interfere, No battery required. When plug with USB flash drive, pls it's FAT or FAT32 format. this only support the USB drive with 6 folders at most, every folder can has 99songs or less. if you set up multi folders , pls also put a few songs out of the folders in the usb flash drive too. This installation and usage are the same as CD change's installation and usage, Simply plug in USB disk/SD card or or android,you can play audio through car audio system and enjoy music in your car. Compatible with: Compatibel with different year and model of only: 2005-2008 2;2004-2008 3 ;2006-2008 6 (see note 3),;2003-2008 Miata/MX5(note 2) ,;2002-2006 SPD, 2002-2003 ;2007-2008 CX7 (see note 2) ;2002-2006 Tribute ;2002--2008 Premacy;1999-2003 323