The description says "Absorbency: Normal, Strong", so this is a size M. (Size S says "Normal, Strong". (Size S says: "Normal, light".
I had also complained to Galaxus that this information was missing from the title/article name, but unfortunately without success.

This is probably the "medium" size, as the description says "normal" and the others "mini". But you're right, a uniform sizing would help ;-)