UMS 5-210cc O-RING (SEALING RING) ( X 10 PACK)

Replacement o-ring (sealing ring) for the UMS 5-210cc, the five-cylinder 210cc four-stroke radial from UMS.

Function: it is a general-purpose sealing ring used at several joints on the engine.

The reason this ends up on an order: O-rings are consumables and harden with heat, so they are renewed rather than reused. Supplied as a pack of 10, which is how these small parts are normally bought — you rarely need just one.

Fitting note: Match material and size to the application — not all O-rings are fuel or oil resistant.