On this parts fiche the O-ring (2h7) is the most specified component.
A sample from the products for the Cylinder include: Pin, Dowel(3gm), O-ring (2h7), Gasket 256113960000 (nas), Gasket, Cylinder Head 1 (nas).
Of all the components that make up this Cylinder the Bolt, Flange(47x) has the lowest price.