Prepare your semi to be Ready for the Road Ahead™, with the National 370120A Red 37 Series Wheel Seal that offers superior axle protection and lubricant leakage prevention. Due to its ability to tightly fit inside the hub assembly, this replacement wheel seal effectively prevents contaminants from entering the wheel, while locking in lubricant. Molded with weather and heat-resistant rubber for optimal durability and performance in challenging climates. FleetPride is your First Click in Heavy Duty®.