Polyurethane is a synthetic material whose chemical structure makes it extremely supple and soft even at extremely low temperatures (-30°C), 40% lighter than traditional thermoplastic blends, highly resistant to animal fats, vegetable oils, manure, fertilisers, acids, fuels, petroleum and hydrocarbons; moreover it provides an excellent heat-insulation (warm in winter, cool in summer) as well as a very high mechanical resistance. These special features result in exceptionally lightweight, safe, shock-absorbing and long-lasting durable Boots.