PAC OS-5 OnStar(R) Interface (Select 29-Bit GM(R) LAN Vehicles). Radio Replacement interface with OnStar(R) retention for select 29-bit GM(R) LAN vehicles with or without BOSE(R) sound system, In-field updateable firmware via USB (using PAC-UP), Retains OnStar(R) when the factory radio is replaced, Retains factory Bluetooth(R) (2009+ model vehicles), Retains rearseat audio controls, Retains factory XM(R), Retains all warning chimes (chime module included), Retains backup sensors/park assist, Retains backup camera signal, Retains factory BOSE(R) audio systems, Retains factory premium BOSE(R) audio (Y91 digital, does not support fading), Supports nonamplified audio systems, Steering wheel control harness (prewired), Dual zone function, Chime volume adjustment (factory buttons), OnStar(R) volume adjustment, Retained accessory power output (RAP), Reverse wire output, VSS (Vehicle Speed Sense) output, Illumination output, Parking brake output, Includes antenna adapter;