Upper: 3+ mm Hydro Perwanger Leather waterproof Lining: Insulated Comfort Gore-Tex® Lasting Board: Carbon insulation Honey-Comb Tech 3 mm Midsole: 2 mm Polyurethane with different thickness on the toe and heel for crampon compatibility Sole: Resoleable Vibram with Impact Brake System, fully crampon compatible. Patent: Registered design