Check out any of the six Reflectors components enlisted.
Parts such as the Reflectors: Bracket,reflector,rr,, Bracket,reflector,fr, Reflector,reflex, Bracket,reflector,rr, are included in the Ksf450-bcs Kfx450r 2012 Usa Reflectors parts fiche.
On this parts fiche the Nut,flanged,5mm is the most specified component.