Direct sound connection will ensure the best sound quality.AUX 3.5mm car audio input: Just plug the device into the extension port of your stereo, connect it to your favourite MP3 player, iPod, iPhone, or Android device and hear the CD quality music right away! Car Smartphone Mounts: Looking for the ways to safely and comfortably use your smartphone in the car? Check out the smartphone in-car mounts available at out store.Car high speed USB chargers: Want to charge your smartphone while in the car? Check out high quality speedy USB socket chargers for cars. Compatibility: Mercedes any model 1994-1998 (not ML series)Each kit contains: GROM-AUX1 module, one vehicle specific data harness, one 3.5mm jack male to male cable operation and installation manual.