I bought a tube marked 26/27½″ for a tire marked “44-622 / 700×45C”. I have another bike w/a 26″ wheel. So despite struggling to trust a dual size tube to be good for either size, I thought it’ll be useful one way or another. But the immediate need is for the 700mm wheel (assuming the “700” means 700mm). That’s 27.56″, which is presumably the same as 27½″ in the world of “nominal” sizes.

The tube does not entirely pack into the tire and the innermost ring of the tube is exposed. Is that okay?

The previous tube was marked 28″. Not sure if that’s the correct size.