The 2004 2005 2006 Acura MDX comes equipped with a BOSE amplifier located next to the pedals underneath the radio. The amplifier powers all of the speakers in the car. This harness will allow you to bypass the factory amplifier and use the factory radio or aftermarket radio to power all the speakers in the car. This harness only works on MDXs from 2004 to 2006 equipped with BOSE. It has the connections for the Front door speakers, rear door speakers and the subwoofer and tweedier.