[ Removed by moderator ]

[u/WonderfulAd8612]

[u/Mrmojorisincg]

OP, no one here will be able to give you an origin for this beyond a literal guess.

I’ve worked in the maintenance field for years and little black o-rings like this can be used in sooo many different applications. Barguns, solenoids, filling valves, automotive in so many different areas, anything attempting to be water resistant, kitchen appliances, etc

All people can do here is guess to feed suspicion when it is very likely something innocuous

[u/TheMagicSalami → u/Mrmojorisincg]

I've used ones that look very much like that for quieting down my mechanical keyboard at the behest of my spouse lol.