This cable is used in conjunction with the MM005 Powered Radio Interface. Simply plug one end of the lead into the interface and the other end of the lead connects to the telephone. On some telephones (incl, Nokia) you will also require a MM012 Base Adapter to convert the plug so that it can connect to your telephone.
If your telephone has radio capability you can listen to the radio as well as make telephone calls.
Please note the main airband radio has priority over the music, mobile telephone & second radio. If these devices are playing audio then this will mute when the airband has an incoming signal.