Product Details: The Hendrickson Hubcap HP Oil with Side Fill Port is the perfect solution for keeping your hub and wheel bearings lubricated. This hubcap features a side fill port that makes it easy to add or replenish oil without having to remove the hubcap. The oil is specially formulated to provide superior lubrication to the hub and wheel bearings, helping to ensure that they are properly lubricated and functioning at their best. The side fill port also makes it easy to maintain proper oil levels in the hubcap, so you can be sure that your bearings are always properly lubricated. FleetPride is your First Click in Heavy Duty®.