On this parts fiche the Packing,protector (nas) is the most specified component.
Parts such as the Muffler: Washer,oil Bolt, Washer,plain,5mm, Packing,protector (nas), Cover B,ex*nh106* are included in the Z50r 1997 (v) Usa Muffler parts fiche.
The most expensive part in this assembly is the Muffler Comp,exh.