it could be a changer control unit, or a Remote port. I am an Automotive Sound Specialist in a garage in chantilly, and i have seen these. most of the time they are for a CD changer or other external accessory. WHat kind of radio is it? Patrick LilRedCivic@xxxx ----- Original Message ----- From: <johndmc57@xxxx> Subject: [DML] My new CD player question By the way, can someone tell me what that thing is in the > middle of the console, it has a plugin jack and is connected to a > black wire under the radio with and end plug that looks like a > computer mouse connector.