I kind of feel there'd be a difference between vulcanised tire rubber and my drink stopper, but I guess there might not be. Also, tires grating on road is proba

I kind of feel there'd be a difference between vulcanised tire rubber and my drink stopper, but I guess there might not be. Also, tires grating on road is probably a bit different a wear profile. Clearly someone needs to test microplastic shredding in container rubber. Oh well, at least they have some in that design with cork tipped plugs. It's a bit harder to find though.