what you see in the pic is what you get.
all thats missing is a valve like this one
which you can put between the cat/exhaust or just after the muffler or where ever you wanna mount it,
you then connect the cable/motor (in the pic) to it which pushes/pulls the valve open/close from an in-cabin switch.
the ecv controls the amount of exhaust flow, which varies the loudness of your exhaust. so if your driving past cops, flick the switch which closes the valve (to a certain point) which quietens down your exhaust