When it comes to getting prepared to tow a trailer, it's easy to focus on the hitch itself. But a hitch won't get you very far without some important accessories. That's because most towing packages -- the factory-installed equipment that transforms a truck or SUV into a tow-ready vehicle -- include a hitch receiver, which is mounted to the tow vehicle, but not a ball mount. The hitch receiver is a square opening, usually 1.25 inches, 2 inches or 2.5 inches on a side (3.2 cm, 5.1 cm or 6.4 cm, respectively). The ball mount is a separate assembly. It slides into the hitch receiver and is secured with a locking pin.
The ball mount needs to match the class of your hitch, which reflects how much weight it can pull. There are five hitch classes, each of which has a corresponding maximum load.
Class I: 2,000 pounds (907 kilograms)
Class II: 3,500 pounds (1,588 kilograms)
Class III: 5,000 pounds (2,268 kilograms)
Class IV: 10,000 pounds (4,536 kilograms)
Class V: Greater than 10,000 pounds
You can't safely tow more than the lowest-rated weight capacity of any individual part, so it does no good to buy a class III ball mount if you have a class II hitch.
Next, we'll talk about what fits in that ball mount.