The Shimano SM-MA-F203P/PA adapter allows the installation of Shimano Postmount caliper on forks and frames with Postmount 160 mm direct style in conjunction with 203 mm rotors. Product features - Shimano SM-MA-F203P/PA Fork-/Frame type: Postmount 160mm (PM6) Caliper type: Postmount Rotor diameter: 203mm Material Adapter: Aluminium Screws: Steel