Our warmest surf booties for the most extreme cold, the R5® Yulex® Round Toe Booties feature 7mm 85% Yulex natural rubber/15% synthetic rubber by polymer content; 100% external seam sealing; a fast-drying inverted microgrid interior lining; and a durable, textured sole for grip. Suggested water temperatures: 32°–38° F/0°–3° C. Fair Trade Certified™ sewn. Made with neoprene-free 85% Yulex® natural rubber/15% synthetic rubber (by polymer content) that meets our rigorous standards for durability, stretch, warmth and sustainability; the natural rubber is derived from sources that are Forest Stewardship Council® certified by the Rainforest Alliance; the synthetic rubber is chlorine-free 95% polyester (51% recycled)/5% spandex inverted microgrid thermal lining is warm, flexible and fast-drying; the lining and face fabric are solution-dyed and laminated with solvent-free AquaA™ glue 100% external seam sealing; all seams are triple-glued, blindstitched and 100% internally taped Y-strap closure conforms to foot for a snug fit; micro gasket at cuff opening prevents water entry Round-toe design for maximum warmth Diamond-grip, nonmarking soles provide increased traction Fair Trade Certified™ sewn Material: 7mm 85% Yulex® natural rubber/15% synthetic rubber by polymer content, lined with solution-dyed 95% polyester (51% recycled)/5% spandex inverted microgrid. Exterior face: solution-dyed 88% recycled polyester/12% spandex. Natural rubber is from sources that are Forest Stewardship Council® certified by the Rainforest Alliance. Fair Trade Certified™ sewn