Keeping the wheels of your trailer well lubricated is an important part of towing responsibly. It may not be on the forefront of your mind, but a trailer's wheels need to be cared for just like the wheels of your vehicle. CURT offers an easy way to give your trailer wheels proper care to help maximize the life and performance of your trailer. Acting like a cap for your wheel bearings, CURT bearing protectors offer two essential benefits for your trailer. First, they provide a reservoir of grease to lubricate your wheels and keep them turning smoothly mile after mile. Second, they cover the bearings so that mud, rain, road grime and other threats to their function are kept out. A bad wheel bearing can start out as a mere annoyance, but before long, it can turn into a huge problem. With CURT wheel bearing protectors, you can ensure that your wheels keep turning, quiet as a mouse. Our bearing protectors also come with plastic dust covers that fit over the end of the protector for even more defense against the elements. Choose a set of CURT bearing protectors for your trailer wheels and get the most out of your towing. This set of bearing protectors features a 1.78\" hub diameter.