The towbar you have selected is a Hayman Reese (Class 4) Heavy Duty Hitch Receiver Towbar with Smartcode wiring.
Hayman Reese’s famous Class 4 Towbar has a 50mm by 50mm hitch receiver and is the heavy duty towing option. Heavy Duty Towbars are often rated to the vehicle’s maximum towing capacity and are essential if towing caravans, large trailers, boats or horse floats. Featuring a special sized hitch section, the Class 4 Heavy Duty Towbar is compatible with all Hayman Reese Weight Distribution Systems (some vehicle/manufacturer restrictions may apply) and hitch mounted accessories. Also included with every Hayman Reese Heavy Duty Towbar is a removable Trailer Ball Mount (TBM), for a neat, flush appearance when removed.
Increasing technological and safety systems on vehicles are now enabling changes to occur when a vehicle is towing. Reverse park assist, blind-spot detection plus various trailer sway mitigation systems are prime examples of vehicle functions that can change if the vehicle is towing. Ensuring that these systems are correctly engaged involves more than simply the wiring and trailer ECU. Vehicles need to be programmed (coded) to allow the towbar harness and trailer ECU to be recognised and integrated into the body control system.