The Men's Patagonia Yulex Regulator Lite Long-Sleeved Wetsuit Top is formfitting and constructed from a stretchy blend of 85% Yulex natural rubber and 15% chlorine-free synthetic rubber by polymer content, with the natural rubber certified by Preferred by Nature. The solution-dyed linings offer flexibility and comfort, featuring an interior of 100% recycled nylon and an exterior of 83% recycled nylon and 17% spandex, laminated with water-based, solvent-free AquaA glue. Designed with flatlock seams for durability and comfort, this streamlined pullover top reduces drag while enhancing flexibility, and includes an adjustable rubberized waist gasket with cord lock for a secure fit and minimized water entry.