The towbar you have selected is a Hayman Reese (Class 4) Heavy Duty Hitch Receiver Towbar.
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 Heavty 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.