Metra Electronics LC-GMRC-05 Custom Fit Data Bus Interface Incl.: LC-GMRC-05 interface/LC-GMRC-05 Harness Custom Fit Data Bus Interface Provides accessory power (12V 10A) Retains RAP For use in both amplified & nonamplified sound systems For use in models without OnStar(R) (if OnStar(R) is present it will be lost) Retains all warning chimes through onboard speaker