Parts such as the F-6: O-ring,37.2x2.4, Bolt,flange,6mm, O-ring, Tube,outer are included in the Cr80rb 1999 He04-250 Japan (jdm) F-6 parts fiche.
On this parts fiche the Bolt,protector is the most specified component.
The O-ring,2.8x1.9 (s is the cheapest item from this partsfiche.