Kenwood Radio Accessories What Kind Of Piece Do I Need To Get In Order For My Navigational System To Work On My KENWOOD Radio System?

What kind of piece do i need to get in order for my navigational system to work on my KENWOOD radio system? - kenwood radio accessories

I have a touch screen in my car radio. In all types of functions such as radio, DVD player, navigation, etc.. But I did buy a piece specifically for the navigation system at work. Not all know the exact name of the play too?