The Towbar Factory's Frequently Asked Questions

The Vehicle Manufacture will generaly indicate the towing capacity of the vehicle in the hand book that comes with it.
It will give you an unbraked rating and a braked rating.
The braked rating is the maximum that your vehicle is allowed to tow at at any time.

There are two different sizes in towballs.The most common ball size is 1 7/8" and has been around for many years. In a rule change a number of years back the Government introduced the 50mm towball, in line with the European regulations. This has brought about a lot of confusion as the 1 7/8" towball fits into the 50mm trailer coupling easily but is a loose fit and is dangerous and must not be done. Most towballs have their size stamped on top of them, and most trailer couplings have there size and towing capacity marked on them as well.
However a 17/8" coupling will not fit a 50mm towball.
There are two towing rates for both types of  towballs, 2000kg rated and 3500kg rated and are generally fitted to match the towing rate of your towbar.