The O Ring(d:1.7,id:6) is the cheapest item from this partsfiche.
Parts such as the Secondary Drive Gear (model K8/k9): Stopper,cam Spring, O Ring(d:2.4,id:90.8), O Ring(d:3.7,id:76.5), Bolt are included in the Vzr1800n Boulevard M109r 2008 (k8) California (e33) Secondary Drive Gear (model K8/k9) parts fiche.
This schematic depicts all components used in the Vzr1800n Boulevard M109r 2008 (k8) California (e33) Secondary Drive Gear (model K8/k9) partslist.