Waterproof Leather Upper keeps feet dry and protected Nylon Mesh Lining for added breathability and comfort Removable Perforated EVA Insert with Gel Technology for comfort and additional shock absorption T901 Outsole performs against oil, water, and abrasion resistant SRX Best-in-Class, Slip-resistant Rubber Outsole reduces the risk of slips and falls on low tractions surfaces Insulated with 200 Grams of Thinsulate patented thermal technology that insulates against the cold, keeping feet warm and comfortable while tackling extreme conditions. Just what you want in your winter work boots