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 * Durable outer sole with inner Nylon-2 neoprene lining for excellent traction