EBC Racing Front Floating SD Rotor Replacement Disc Ring (Front Left) - Audi / B7 / B8 / RS4EBC Replacement Rotor Rings have been rigorously tested to ensure they can endure hundreds of hours of the most demanding track driving. Each cast iron ring has 48 curved vanes oriented left and right, ensuring that the vanes rotate in the proper direction for maximum cooling effectiveness. All outer friction rings are made of a high copper, high carbon G3500 disc alloy, which provides excellent wear and crack resistance, even when utilized on the