It means that the controller and hydralic valve is already installed in the tractor. 

For an original greenstar system you need a reciever, keycard, display, and mobile processor. About $6500 using all new components for an SF1 setup. Less if you can find used.

For GS2 you'll need display, activation, and reciever. $7500 setup with the small non-touchscreen (no documentation) or $10,500 for the 2600.