The Wilwood Forged Superlite Radial-Mount Brake Caliper Mounting Brackets are manufactured from high strength aluminum alloy with an e-coat finish. Bracket set 250-6309 is designed for any 3.50”mount center. Bracket mounts superlite series radial caliper and 12.19 diameter rotor. Will fit 11.75 diameter rotors when original equipment and mounts were designed for 11.75 diameter.