Metra XSVI-5520-NAV Non-Amplified Non-OnStar Harness to Retain Accessory Power Provides accessory power (12 volt 10 Amp) Retains R.A.Tpu (retained accessory power) if equipped Provides navigation outputs (reverse/parking Brake/vehicle speed sense) Used in non amplified systems or when removing the Sony/THX amplified system Usb updatable and in new case The XSVI Interface series provides a 12V accessory power output that uses data control signals instead of conventional power signals 12 Volt Accessory Interface Provides VSS (Vehicle Speed Sense), parking brake, and reverse signals to an aftermarket navigation receiver, making the installation easier R.A.P. (Retained Accessory Power) function is retained