The Metra is designed to be used in a non-amplified GM vehicle or in vehicles where the OEM Amplifier has been bypassed On Star will not be retained. This harness retains all the factory warning chimes that would be lost when the OEM radio is removed. It also provides a 10 Amp 12 volt switched accessory for proper radio operation and to retain the RAP feature if equipped.Features. Class 2 Data Bus Interface for select Cadillac Vehicles. Includes R.A.P Retained Accessory Power. Provides a 12V DC 10 amp accessory output. Built-in speaker retains all warning chimes. Used in non-amplified systems or when bypassing an amplified system. Does not retain Onstar. USB Updatable Firmware with USB-MINI-CAB or AX-OTG1AN. Authorized Internet Dealer