New from HPI for the 2004 ROAR National Champion Pro 4 are these POM (polyoxymethylene) Bearing Adapters that allow racers to install smaller lightweight bearings in the Pro 4. In the fiercely competitive Touring Car class, even small weight savings can mean the difference between winning and losing. These adapters are machined from high-strength POM plastic for a factory-precise fit! 8 adapters are included in each package. POM (polyoxymethylene) is an advanced, aerospace polymer material that is extremely durable, lightweight and strong, providing the perfect mix of characteristics that make it ideal for racing applications!