Works on: 2008 2009 2010 Cadillac CTS w/o PROX, 2006 2007 2008 2009 2010 Cadillac DTS, 2007 2008 2009 2010 Cadillac Escalade, 2007 2008 2009 Cadillac SRX, 2004 2005 2006 2007 2008 Cadillac STS. This is a transponder key (chipkey.) Any locksmith can cut the key to match your existing key. Then use the included easy instructions to program your car to accept the new key so it will start the engine. Free phone tech support included as needed.