If you have a bose system and want to upgrade the head unit you no longer have to use the pac unit and wire up 8 different wires to wire it in with the bose system.
Now the plug and play unit plugs right into your rca jacks of your new unit that is it!
Nissan/Subaru Receiver Wire Harness For select 2007-up Nissan and 2010-up Subaru models at Crutchfield.com