The Washer Seal, 6mm is the lowest priced item on this Oil Filter / Oil Pan schematic.
With all the components that make up the CB550SC NIGHTHAWK 1983 (D) USA OIL FILTER / OIL PAN assembly. The Bolt,flange,6x28 is the most frequently specified with fourteen applications.
Parts such as the Oil Filter / Oil Pan: Washer,plug,drain 12, Element Set,oil, Pan,oil, Oil Pan are included in the Cb550sc Nighthawk 1983 (d) Usa Oil Filter / Oil Pan parts fiche.