This is a small connector which was part of the original subwoofer setup on the back door of Discovery 2 models. Typically with our subwoofer upgrade kits you would snip the wires off the back of the original subwoofers (they are soldered in place) then crimp the provided terminals and refit with the new subwoofers........
......the problem is that we have had a few occasions where the subwoofers have been removed from the vehicle leaving nothing for the speakers to connect to, so we made these little patch looms for customers that have not got this part of the setup left in their vehicle.