Use this adapter to make your installation of a subwoofer bass amplifier to the factory system faster with a cleaner install. Use this plug and play adapter so you don't have to cut or splice into the factory wiring. Provides rca output and a power wire for the remote amplifier turn on connection. Adjustable gain output. Not compatible with factory premium amplified stereo systems. Not compatible with vehicles with an external factory amp. Connection is done at back of radio unless specified below. Some years don't connect behind the radio- some connect at the radio tuner usually located at the passenger kick panel or behind the glovebox area. Compatible vehicles: No factory external amp vehicles: Made for Mazda: 2001-2002 626, 2016-2021 CX-3 (at kick panel), 2013-2015 CX-5, 2017-2020 CX-5 (at kick panel), 2007-2012 CX-7, 2007-2015 CX-9, 2011-2014 Mazda2, 2004-2018 Mazda3 (2014-2018 at kick panel), 2006-2015 Mazda5, 2003-2021 Mazda6 (2014-2021 at kick panel), 2003-2006 MPV, 2001-2020 Miata (2016-2020 at kick panel), 2001-2004 Protege, 2002-2006 Tribute, 2004-2011 RX-8