Premium Rotors are blank, 1-piece, direct replacement discs for your factory brake system. These "black" rotors feature a special anti-corrosion e-coating that gives them their distinctive look and name, and are manufactured under QS and ISO quality system standards. Centric Premium Rotors are particularly desirable in fleet or emergency vehicle applications when an upgrade to StopTech Sport rotors is not possible. Like many StopTech 1-piece rotors, Centric Premium Rotors offer several key advantages over stock rotors, E-coating, Double Disc Ground, Machined Finishes, Symmetric Vane Castings and Mill Balancing are just some of the processes we use.