Hard rubber (ebonite) is a heavily vulcanized rubber that is rigid and non-elastic, used in items like bowling balls and electrical insulators rather than apparel. It is classified under a separate hard rubber articles heading. Soft vulcanized rubber, which retains flexibility and elasticity, is what qualifies here. Importers can confirm the distinction through Shore hardness testing or supplier material specifications.

Rubber waders and similar full-body protective garments of soft vulcanized rubber may fall here if no more specific provision applies. However, certain diving suits and wetsuits may be classified under sporting goods or other specific headings depending on their construction and intended use. A binding ruling from CBP is advisable for high-volume imports of specialty rubber garments where classification is not clear-cut.