WordNet records no synonym and no antonym for mobius strip. It is the only member of its synset, which is common for technical, taxonomic and single-sense vocabulary — there is no other English word that means the same thing. The broader and narrower terms below are the useful relations in that case.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
a continuous closed surface with only one side; formed from a rectangular strip by rotating one end 180 degrees and joining it with the other end
Synonyms, antonyms and the broader and narrower relations for mobius strip come from Princeton University’s WordNet. Full sources and licences.