The Men's Patagonia Yulex Regulator Lite Wetsuit Vest is formfitting and constructed with a stretchy blend of 85% Yulex natural rubber and 15% chlorine-free synthetic rubber by polymer content, with natural rubber certified by Preferred by Nature. It features solution-dyed linings for enhanced performance and comfort, with an interior made of 100% recycled nylon and an exterior composed of 83% recycled nylon and 17% spandex. The linings are laminated using water-based, solvent-free AquaA glue, creating a lightweight and flexible vest ideal for warm-water conditions.