ATV 50mm tow ball. The hole for the towball on most 4 wheel motorbikes is smaller than on a car.
This small shank towball fixes the problem.
It is stamped and rated to 3500lbs (1.5 tonne).
Ball diameter: 50mm
Shank diameter: 18.90mm
Shank length: 50mm
Double dipped chrome plated
Includes spring washer and nut
Measurements are on photos