When installing the PXAMG Gateway adapter into select GM Class-II Radios with "BAND" button (satellite radio ready), a vehicle specific harness is required. The PGHGM5 will allow GM Class-II radio owners to install Peripheral PXAMG iPod/HD Radio adapter to the select 2003-07 GM Class-II Radios listed in the APPLICATION GUIDE (You must open the application guide to verify if you vehicle is listed)