Engineered, seamless Drylock ankle seals keep water out and warmth in * ThermoCarbon heat-retaining lining made of bamboo charcoal infused fibers and recycled fibers * UltraStretch neoprene ankle panel for easy on and off * Glued and blind stitched Pressure Bonded taped seams * Adjustable Velcro strap and pull loop are Pressure Bonded to boot for maximum durability