The Dirt Tricks Beta rear disk brake rotor is the ultimate combination of durability, wear resistance and stopping power. They are incredibly strong and will resist bending unlike anything else on the market today. They are Black Zinc plated to prevent rusting. These rotors have been developed and tested for nearly one year by engineers with the assistance and test riding/racing of Shane. Every rotor includes a One-Year Warranty! Like the Dirt Tricks Sprockets, if you want the toughest race products, choose what professionals race. Two to three times higher tensile strength than O.E.M. rotors, resulting in much higher resistance to bending and wear. Made of heat-treated alloy steel, providing higher stopping friction, therefore 25% less braking effort. Three times the cooling rate of stainless steel rotors. If they cool three times faster they run cooler all the time.