This is a peripheral gmaa. Used to add an amp and turn on lead to gm's premium bose equipped vehicle. These sell for over $100 new and Ill let this one go for $65shipped in the usa. The turn on lead senses off the can bus data line and turns on and off with the volume knob on factory radio. No thumps pops or problems. Heres a list of vehicle's it will work with.
http://www.peripheralelectronics.com/seeAllApps.aspx?ProductID=155&ProductName=GMAA
http://www.peripheralelectronics.com/seeAllApps.aspx?ProductID=155&ProductName=GMAA
