Saute-Mouton boots are made with waterproof leathers. These leathers have been treated with waterproofing agents during the tanning process. This allows a deep resistance, not to be confused with surface-treated leathers. Shoe construction is also waterproof : the seams of the foot section are sealed with cement glue, as are the outsoles. Obviously, our waterproof guarantee does not apply to zippers and eyelets. We use the best hardware available, like YKK zippers. Lining of our leather boots is made of woven sheep wool on polyester fiber. This lining provides maximal heat for maximal uses. Higher boots have a wool-lined foot section and synthetic fabric-lined leg section to keep your leg dry. Our sealskin boots and our Nordic collection are lined with sheepskin. Our outsoles are made of a thermoplastic-rubber composite in proportions varying depending on our suppliers. We only use outsoles designed for winter.