Required adaptor to fit a flatmount calliper to a flat mount fork,Reversible design works for 160 and 140mm rotors,Lightweight self aligning design,No need to face your forks or frame, the adaptor will compensate for any paint or frame imperfections,Precision laser cut from the best quality, most durable aluminium,Very stiff to resist torsional forces, yet weight removed wherever it has been possible to achieve safely,Compatible with virtually all brands of hydraulic and mechanical Disc callipers.