APPS2Car Car Stereo 3.5mm AUX Jack Adapter Muisc Changer for Audi A4 R8 TT S4 A3, Volkswagen VW Jetta Beetle Passat GTI Golf Tiguan EOS Polo Touran Rabbit R32 T5, Skoda Octavia SuperB, Seat Leon Altea Offer your factory radio into an auxiliary input to provide you digital sound quality and compatible with most device, such as iPhone, iPad, iPod, Android Mobile Phone, MP3 player, XM Satellite Radio, Video Game Systems, DVD player, etc. Support control music via steering wheel control or radio panel button (track + / -) Gold Plated 3.5mm AUX Input Jack enhance Hi-Fi line level sound quality. No Signal Interfere. No Battery Required. Please double check the compatible list before place an order. Plug & play. Installed via OEM CD changer port, integrated with the car radio. (The ground wire with loop need to be hook up to the car radio metal body.)