Bluetooth connects to your phone and sends the signal from your phone to the speakers. So with this setup I can play music from my phone to my car speakers. In my radio (moparmikes is alot fancier than mine) basically its just a prop to look original the only function it has is the volume knob. Everything else is gutted and does nothing but appear original lol the knob still turns the tuner and the needle still moves but it dont do anything.