PAC OS-311 Onstar Interface (GM 14-Pin and 16-Pin): * Replaces factory radio in 2003 - 2006 GM SUVs and trucks while retaining OnStar * Plug and play, no cutting or splicing into factory plug * Pacos2/Pacos2Bose communicate directly with the OnStar module to prevent false * Triggering and eliminating unwanted audio noise * On-board amplifier will drive two 4W speakers in stereo * Use with the existing factory speakers or external speakers * GM 14-pin and 16-pin