Rated for water 40 degrees and upn100% Titanium Memory Foam with Aquasilk LiningnSeams double glued and blind stitched for durability and to keep the cold water outnOne-way flow vent purge valve vents regulator exhaust away from the hoodnAquasilk fabric is pill and abrasion resistantnHenderson's exclusive H2: ultra-soft, low modulus, extended memory foam rubber with titanium lining is simply the best, most comfortable and technically advanced hood material available anywhere. H2 offers the same 250% stretch as with the original Hyperstretch but with a revolutionary interior and exterior fabric laminate called Aquasilk. This exclusive combination of rubber and fabric provides the same great stretch which made traditional Hyperstretch so popular, but with a bit more compression to keep the hood from ballooning. Ballooning, caused by excessive stretch, may allow cold water entry during initial surface entries. The Exclusive Aquasilk advancement in synthetic fabric technology provides the pill resistant and rugged durability required for the dive environment with an ultra-soft and supple "hand" found traditionally in natural fabrics. H2 hood is 7/5mm in thickness, has glued and sewn seams and flow vent to release trapped air. Hood is available in multiple sizes.