Patagonia Men’s Yulex Impact VestFeatures With flexible foam panels for additional flotation and impact protection in heavy surf, the Yulex Impact Vest is made from stretchy 85% Yulex natural rubber 15% synthetic rubber by polymer content. Fair Trade Certified sewn Made with Natural Rubber Stretchy 85% Yulex natural rubber 15% synthetic rubber by polymer content; the natural rubber is Forest Stewardship Council certified by the Rainforest Alliance; the synthetic rubber is chlorine