Product Details: Get your semi truck Ready for the Road Ahead™ with protected hub caps, with the Stemco 1-1/8" Rubber Vented Hub Cap Plug - Red. With a straightforward design, this rubber plug works to seal out contaminants such as dirt, water, and oil before they can enter the wheel assembly. Crafted with an additional sealant to increase overall reliability. FleetPride is your First Click in Heavy Duty®.