100% Waterproof, Rugged MS-1 molded outsole, 5mm CR Flex-foam, Fleece lining, 2mm thermal foam under the footbed, Double reinforced heel, instep and Achilles, Cushioned EVA midsole, Comfort Range: -40 to 40F, 13" upper shaft, Muck Boots set the standard for rugged dependability. These fleece lined, high-performance Arctic Sport Boots are 100% waterproof and feature double reinforcement at instep, heel and Achilles, and a lightweight EVA molded midsole with contoured footbed for supreme comfort and cushioning. A 2mm thermal underlay adds extra insulation on the inside, while the rugged MS-1 molded outsole and wrap-up toe bumper provide optimal traction, durability and protection on the outside. The stretch-fit topline binding keeps snow out and warmth in, so you tackle any cold weather task with confidence.