You can find all the spare parts you need from the best brands at Escapa.
Magura Flatmount QM 52 Adapter, Front Wheel F160/180-160
1 adapter
2 M5x10 countersunk screws (T25 screw head)
2 x M5x14 flat-mount screws (T25 screw head)
Compatible with MT4 FM, MT8 SL FM, and MT C4 FM brakes