These Trojan Towballs are specially designed to be used on NZ fixed tongue towbars (75mm wide). The 50mm High Rise Towballs and Locking Plates are the Manufacturers' mandatory requirement for use with the imported European Caravans fitted with the AL-KO AKS Stabiliser Couplings. 
The Adapter Locking Plate is required to stop the nut from being undone when attached to the coupling.
 
3500kg tow rating
2 shank diameter options are available
22mm (7/8")
25mm (1")
Shank Length: 65mm
25mm higher than a standard towball
 
Please note that the towball nut must be tightened to 220mm torque to ensure there is no ball movement.
 
Due to the type of steel used to enable necessary grip for the stabilizer head these are prone to minor surface rust on the ball and shaft.  Should this happen we recommend a coat of paint on the shaft but NOT the head as it impacts the friction.  Recommend using the ALKO Towball cover or the Maypole Towball cover with these.