Parts such as the Rear Hub: Sprocket-hub,48t,al, Nut,castle,22mm, Washer-plain-small,8m, Collar,rr Hub are included in the Kx450fcf 2012 Europe Rear Hub parts fiche.
On this parts fiche the Washer-plain-small,8m is the most specified component.
The Washer-plain-small,8m is the lowest priced item on this Rear Hub schematic.