On this parts fiche the Collar,ex.joint is the most specified component.
This schematic depicts all components used in the Cb550f2 Super Sport 550 Four 1977 General Export Mph Exhaust Muffler partslist.
A sample from the products for the Exhaust Muffler include: Spg-washer 8mm, Bolt,muffler Set, Pipe Comp,exhaust, Bolt,hex.,6x25.