Adding an auxiliary input to your factory Chrysler radio enables you to plug in devices such as MP3 players, portable DVD units, iPod iPhone, Android and other mobile electronics to be played from the factory Chrysler stere. In order to add an aux input to your vehicle, you need to purchase an aux input kit that plugs into the back of the radio and provides a 3.5mm jack that runs into the dash, glove box, center console etc so that it can be plugged into your MP3 player or other media devices.