FLEXIBLE AND WARM WINTER BOOT FOR ACTIVE PEOPLE Fleece lining, stretch-fit shaft top retains heat inside and the cold outside, 5 mm CR flex-foam with four layers of stretch lining, light and comfortable, 100% waterproof, MS1-molded outsole, robust, durable and durable for maximum protection and stability, double reinforcements at the ankle and heel, 2 mm foam base for additional warmth at the ankle, EVA-molded midsole with rounded footbed. Comfort heat from -40 to 15 degrees.