Shimano Spares Adapter i/Standard for Rear Black, 20.3 cm

Amazon

Interchangeable, precision engineered disc calliper mount adapter For post type disc callipers to be mounted to international standard frames with 203 mm disc rotors Durable Model number: 2090325000

Blacks

Interchangeable, precision engineered disc calliper mount adapter.Key Features:For post type disc callipers to be mounted to international standard frames