Boost your warmth level with the supplementary O'Neill Thermo-X Long Sleeve Crew. Soft, stretchy and odor resistant, the Thermo is a smart accessory for the savvy cold water surfer. Put the Thermo-X Crew on under your existing wetsuit to dabble into colder seasons or to extend an older suits life until a new one is on its way. A cold nipping layering piece that offers an additional shield of core warming protection, the O'Neill Thermo-X Long Sleeve Crew gives incredible insulation with minimal bulk.