Magura QM46 Disc Brake Adapter Adapting All Day If you need to adapt a post mount to work with a bigger rotor, you'll need an adapter. The Magura QM46 Disc Brake Adapter is designed to mate Magura disc brakes with a variety of frame mounts and rotor sizes. The QM46 adapter adapts 220mm rotors to 203mm post mounts. It includes hardware to mount the adapter. Features Adapts a Magura 220mm rotor to a 203mm post mount Includes the hardware to mount the adapter to the frame Manufacturer's part number: 2-702-193 | Magura | Qm46 Disc Brake Adapter Pm 203-220