The Roadmaster Chrome Front Hub Cap is designed to provide superior performance and durability. This hub cap is constructed with an embedded aluminum ring that evenly distributes load and a molded pressure ridge that improves sealing ability. It features a proven center-fill vented plug-in design and a side fill plug that incorporates an O-ring for extra leak protection and a magnet that traps metallic particles. The patented umbrella style valve seals keep out contaminants and dust, ensuring a long-lasting, reliable performance. FleetPride is your First Click in Heavy Duty®.