These MX-5 Miata coated, run-true rotors are manufactured to match the exact OE fit, construction, and precision finishing to ensure quick and easy installation, as well as trouble-free functionality for the life of the rotor. A grey coating is applied to all outward non-friction surfaces including in the gap between the plates covering the cooling vanes which is cured through an oven drying process. This coating provides an effective anti-rust protection to keep your Miata wheels looking good! Sold individually.