The IS77 is designed to provide the connecting link between your audio source and your FM radio. Using the supplied accessories, you can connect virtually any audio source into any FM equipped radio. This interface has a universal input that can be configured to accept an audio signal from any source with an RCA connection or a standard 3.5mm ï¾“Headphoneï¾” output. The IS77 will route the audio from your device through your factory or aftermarket radio without a built in auxiliary input. If your audio source is an iPod featuring a docking connector, this interface will also charge the iPodï¾’s battery, when connected.