USB Sd AUX Mp3 Interface Digital Cd Changer for Peugeot Citroen Rd4 Rt3 /(Rd4 Radios By Bosch/ Blaupunkt) w/16GB USB Flash Drive _HUAHEE Yatour digital musci changer is a replacement of CD changer. It can be easily installed and used. Not change car original function . With Usb Sd Aux interface.Support play songs from SD/SDHC/MMC card, USB stick ,Aux device . Bluetooth adapter is optional . It can make travel more entertaining and increase. Come with 16GB USB Flash Drive(Gift)