Provides accessory power (12-volt 10-amp), Retains R.A.P. (Retained Accessory Power), Used in amplified systems, Retains chimes and balance and fade, Provides NAV outputs (parking brake, reverse, mute and speed sense), Retains OnStar/OE Bluetooth, Adjustable gain control for chimes and OnStar, High-level speaker input, USB updatable.