Its main function is to preserve the hitch ball in good condition, ensuring an effective connection between the towing vehicle and the trailer. There are several reasons why you might consider purchasing a hitch ball cover. Exposure to weather such as rain, snow, moisture and chemicals can cause corrosion of the hitch ball. A ball cover creates a protective barrier that helps prevent rust and prolongs the life of the hitch. It prevents dirt, mud and debris from accumulating on the hitch ball, keeping it clean and hygienic, and improves the aesthetic appearance of the hitch.