Prevention of rust and corrosion with clear-look coating protection All QuietCast rotors are factory mill precision balanced, which disperses the weight evenly and allows for smooth operation Smooth pedal feel and safe stops assured by industry-low run-out and DTV specifications ...Prevention of rust and corrosion with clear-look coating protection All QuietCast rotors are factory mill precision balanced, which disperses the weight evenly and allows for smooth operation Smooth pedal feel and safe stops assured by industry-low run-out and DTV specifications Superior cooling, increased performance, and longer life provided by OEM-style vane configurations The on-the-part Bosch brand ensures quality and the discard thickness lets you know when the rotor has reached it useful life