The Washer,plain, 6mm is the cheapest item from this partsfiche.
A sample from the products for the Air Cleaner / Side Cover 79 include: Band, Side Cover, Cover, A/clnr Hsg, Rub,air/c Mount, Pkg,cleaner Case.
The thirty-eight Xl75 1979 (z) Usa Air Cleaner / Side Cover 79 component parts are all listed in this schematic.