Baffin Crossfire Snow Boots - Men。The Baffin Men\'s Crossfire boots are high-performance winter boots featuring a comfort rating of -40°F [-40°C]. Temperature Rating: Down to -40°F [-40°C] (Tundra rated) Upper Material: Waterproof Double Weave 900 Denier Nylon and Leather Insulation System: 7-layer removable inner boot system (includes B-Tek Heat, Vapourized Aluminum membrane, and Thermaplush) Base & Outsole: Arctic™ Rubber Shell with an EVA Midsole and Polar™ Rubber Outsole Lacing System: Speed-Lace front fastening system with a pull-loop at the back for easy entry.