Ford mp3 AUX input converter, for radios with AUX button 04 and up Ford f150 audio input Mustang aux input The FRD04-AUX interface connects to the back of the Ford radio and converts the DVD port in to an audio input port creating a new source, audio input aux for radios with Aux button 2004 and up connects to the 16-pin connector that is located on the back of the Ford factory radio This interface lets you input audio from any portable source like mp3 DVD player iPod iPhone satellite or just about any external audio device by converting the Ford rear DVD plug on the factory radio into an auxiliary audio input. anything can be added to the Ford radio without Fm modulation this is not a wireless transmitter or FM modulator that means the signal isn't getting degraded by the process of sending it to your ford radio, radio must have an Aux button no sat button, works with single CD player or in dash 6 CD changer AAI-FRD04 and frd04aux are the same part FRD04-AUX has a built-in audio adjustment gain control input of 0.475 volts to 4.75 volts (peak to peak) allowing you to match the audio level of the Aux device