Waterproof Synthetic Leather and Hydrophobic Ripstop Nylon: All-weather protection. Removable Memory Foam Insole: Superior comfort and easy maintenance. Laced-Up Boot with Barrel Lock Closure System: Secure and convenient fit. Synthetic Sheep Wool Lining and 200 g Thermolight Insulation: Optimal warmth for cold winter days. Waterproof, Flexible Synthetic Rubber Shell and Outsole: Provides grip and stability on all surfaces.