This interface allows the CAM-MS-SBR to be connected with Bluetooth capable phones and media players for wireless streaming music. A2DP music streaming allows you to advance the songs on your phone buy using the track up/down button on the radio. It will also mute the music to take a hands free phone call through the radio. If you have a CD changer or CD1 single player you can still use it with the adapter plugged in (there is a CD changer port on the control box of the Bluekit).Main control box has a 1.5' cord that goes to radio CD port, 6.5' cord to Bluetooth button and 3.5' cord from Bluetooth button to microphone.