Wave? Brake Rotor - Rear - Black Carrier Made from 420 high-carbon stainless Tier-1 steel, Laser cut, stamped, Each rotor is individually heat-treated and double-disc parallel ground to ensure -flatness, WAVE? design allows for lower operating temperatures at extreme conditions, WAVE? design is much lighter than a stock rotor, For maximum braking performance and longevity, Galfer recommends using Galfer brake pads with Galfer rotors.