PAC OS-4 Radio Replacement Interface for 2006-2007 GM LAN Factory Radio Replaces factory radio in GM SUVs & trucks while retaining OnStar Plug & play, no cutting or splicing into factory plug OS-2/OS2-BOSE communicate directly with the OnStar module to prevent false triggering and eliminating unwanted audio noise On-board amplifier will drive two 4-watt speakers in stereo Use with the existing factory speakers or external speakers