to cut it short pip you need an alko type tow ball refitting to the tow bar,they are aroun
The standard towball clearance from the tow bar mounting face to the towball centre is 58mm (2.25") and vertical clearance is 45mm (1.75")The degree of articulation is covered by international standards and the Alko coupling has no specific requirements in this respect but, as Matthew correctly states, the standard clearance of 65mm between bumper and towball is inadequate for the Alko, which needs about 80mm. To my knowledge, all swan-neck towbars provide adequate clearance for the Alko.