Extreme is a warm thermal boot with an award-winning design and many smart details - a favorite for both children and parents. Thanks to the polyurethane construction with adjustable cuff, Extreme is waterproof, light and comfortable enough to wear all day. The boot is made of a flexible polyurethane material called Elastopan® and is a 100% PVC-free, degradable material that contains millions of tiny air bubbles and is 40% lighter than PVC and rubber. Viking thermal boots provide 2.5 times better insulation than regular PU boots and are twice as durable. Thanks to the wool and polyester lining, Extreme provides effective insulation for children's feet down to as much as -20 ° C. The boot's sole is made of TPU, which is slightly heavier than PU but which is non-slip and very durable. Extreme is a proven and durable winter classic that is perfect for wet, snowy and cold weather.