Axxess GMOS-014 GM Factory Integration Interface OnStar and Chime Retention Module for 2000-Up Select GM Vehicles GM Factory Integration Interface OnStar & Chime Retention Module For 2000-up Select GM vehicles Designed to retain Onstar and warning chimes that are normally lost when OEM radio is removed Provides a 12 volt accessory output for aftermarket radio operation Reverse output to make installing an aftermarket navigation radio simple