See below link for additional info - allows an owner to maintain the existing stock audio unit and with this unit, connect an iPod / iPhone / (or possibly an Android with the correct adaptor) and use the music functions on the device via the stock audio unit. May also be compatible with other GM vehicles within that the mid-2000's model years. Originally sold for $300.00 US, I believe. Device works - I just no longer need it and have no use for it. 2 units are available. PRICE DROP!! http://www.kawal.net/PAL%20Rev%202.htm http://www.kawal.net/PAL%20Start.htm