When you're transporting your boat, you're probably not thinking about the condition of your trailer's wheel bearings. And with a good pair of dust caps, you don't need to. Keep the dust and other debris out of your trailer's wheel bearings with these quality metal dust caps, which fit onto the center of your trailer's wheels. Without them, dirt, dust, and other foreign materials can enter the bearings and contaminate the lubricant inside, which causes excessive wear on the bearings. The black rubber inserts that are included in your order increase the amount of protection that the caps provide. They measure 1.98 inches, and can serve as a direct replacement for 229-00233-NA-A and 229-00115-NA-A. We ship orders each day, which ensures that you'll receive your products as quickly as possible. And in the unlikely event that we don't have the parts you've ordered in our inventory, we're able to get them directly from the factory.