Bosch QuietCast Premium Disc Brake Rotors utilize innovative materials that ensure the highest quality performance, prevent rust and corrosion with clear-look coating protection, provide a clean look for today's open-wheeled vehicles, are 100% precision balanced for smooth ...Bosch QuietCast Premium Disc Brake Rotors utilize innovative materials that ensure the highest quality performance, prevent rust and corrosion with clear-look coating protection, provide a clean look for today's open-wheeled vehicles, are 100% precision balanced for smooth operation, and have a factory-engraved edge with code and minimum thickness specifications. Professional installers recognize Bosch as OEM and can be assured Bosch QuietCast Premium Brake Rotors provide the highest quality to the aftermarket, from the company with over 70 years of OE braking expertise.