The IPBCK, designed for third and fourth generation iPods and iPod minis, or UBCK designed for universal MP3 players, will work with aftermarket head units with RCA inputs. For those who like flexibility with their music, the Bluetooth interface will allow a passenger in the front or back seat to control the iPod or MP3 unit playing through the vehicle's head unit. Included in the vehicle kit are a 12volt car charger, rechargeable transmitter, and the necessary cables for a simple installation.