Award winning design, kid tested and parent approved- Extreme Warm is a warm, comfortable waterproof boot for all-day wear. Constructed from Elastopan, Extreme Warm is 100% PVC-free, 40% lighter than comparable PVC or rubber boots and offers 2.5 times more insulation than normal PU boots with twice the durability. With the help of a wool blend liner, Extreme Warm effectively keeps feet warm down to -20°C. The sole of this boot is made from TPU known for its excellent wear and non-slip properties.