PAC OS5 OS-5 Radio Replacement Interface with Onstar Retention Retains OnStar when the factory radio is replaced Retains Factory Bluetooth (2009+ model vehicles) / Factory BOSE audio systems.Illumination output, parking brake output Retains rear seat audio controls Retains all warning chimes (chime module included) Retains back-up sensors/park assist/back-up camera signal Replacement interface for select gm vehicles with OnStar, Bose, and gm LAN data bus Compatible with or without factory amplified audio system1 Can be used if the vehicle does not have OnStar Compatible with or without Bose systems Retains the 5.1 Digital audio system in select gm vehicles