Check out any of the twenty-five Rear Hub components enlisted.
In this schematic the "Washer-plain-small,8m" is used most often.
Parts such as the Rear Hub: Drum-assy,rear Brake, Sprocket, Hub, 48t, Sprocket-hub,51t, Axle,rr,l=255 are included in the Kx450hhf 2017 Europe Rear Hub parts fiche.