PAC RP5-GM11 Radio Replacement Interface (RadioPro5, Select GM Class II Vehicles with OnStar) Radio replacement interface; Retains chime functions; Outputs for navigation radio functions; Interface can be quickly updated if needed from PAC(R) website using PAC-UP USB adapter; For GM(R) Class II vehicles; Retains OnStar(R) functions; Compatible with Bose(R) & standard sound systems;