Rated to -40°F/-40°C. Waterproof insulated mid-calf boot designed for extreme weather. 2.0-2.2mm waterproof full grain leather. Hvyent waterproof/breathable barrier. 400 grams Primaloft insulation. Dry-lex fleece collar and tongue lining. Outlast footbed absorbs excess heat and releases stored heat as needed. Injection moulded waterproof TPU shell with forefoot flex grooves. injection moulded nylon shank insert with dual density X-2 footbed. EVA midsole. TNF Winter Grip rubber outsole.