3.5mm connection audio cable to Pioneer IP Bus radios. Use to add an external stereo source directly into the radio for static free sound. Connects to the IP-Bus cd changer port on Pioneer/Premier aftermarket car radios. | VERY IMPORTANT--Please Read--- Radio has to have the Pioneer P-Bus square cd changer port in back of the radio. Connects to the cd changer port so anything connected to it including the external cd changer has to be disconnected. The 3.5mm connector is not designed for continuous disconnecting and connecting- it will eventually wear out and stop working- using an extension cable is recommended for easy replacement of the extension cable instead of this cable. | Installation note: some radios require that the Aux Input function be turned on in the radio's menu.