Connect through the car CD player directly,Non-destructive installation. Control sthe music play and volume by Car radio panel or the steering wheel. Support 3.5mm AUX audio input. High quality MP3/WMA decoder, let the music more pretty. With no Signal interference,no need to install baterry. ,easy to install and use. Universal Compatibility: Play audio from any phone, tablet, for , laptop or other media-playing device on your headphones, Hi-Fi or car stereo (fits standard 3.5mm aux ports). : Ultra slim extensions to the aux jacks enable use with pretty much any phone or tablet case (unlike standard aux cables). No need to remove cases during use. Compatible with (Car Model and Year): for 1999-2005 A2,2001-2006 A3,1998-2006 A4/S4,2001-2004 A6/S6,1999-2003 A8/S8,2000-2005 Allroad,1999-2003 TT. Product parameter: voltage Input:12V DC Signal-to-noise:90dB Max.current:35MA Power: 0.42W harmonic distortion:0.01% requency response:20HZ-20KHZ Signal to noise (1KHz out=800mv )75DB working temperature :-30C-80 Audio supports lossless formats wav , mp3 , mp4 , wma MP3 WMA DTS PCM decoder type: Car AUX Adapter color:Photo color Material:plastic Package Contents: 1 x Car AUX Adapter Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.