The most noticeable difference from the stock rotors is that the Vette Brakes rotors have grooves cut into the surface of the rotor. This serves two purposes. The first objective is to allow the gasses that are generated when braking a means to escape from between the rotor and the pads. Also, the trailing edge of the groove is cut smooth to prevent the rotor from gouging into the pads when heat expansion takes place. This means that each rotor is designed and marked for a specific corner of the car, and you need to be careful that you install each rotor in the appropriate hub.