Magura - QM40 Adapter 180mm Rotor (front) or 160mm (rear) Post Mount - SoCal Bike - Oceanside, Carlsbad and north San Diego county's favorite bike shop, Bicycle and ebike rentals, sales, and service
Magura QM+20 Post Mount disc brake adaptor
Magura QM 42 Brake Disc Adapter - Urban Bike Society