The Arctic Sport TM is warm enough for the coldest outdoor days, and durable enough for the most rugged conditions. Breathable Air-mesh lining with Stretch-fit top-line binding snugs calf to keep warmth in and cold out. Molded, durable, rubber out-sole provides maximum protection and stability. Added toe protection and foam underlay added to the instep area for additional warmth. Reinforced toe and double reinforcements on the instep, heel and Achilles area. Snag-resistant cover is 100% waterproof, lightweight, flexible, buoyant, and will form to virtually any calf girth. Comfort range of 16C to -40C. Unisex sizing on every boot: Women's sizing is one larger than men's.