Oboz Men's Big Sky Mid Insulated Waterproof Boot Synthetic Lug Sole sole Upper: Oiled top grain leather, 200 gram 3M Thinsulate insulation, Oboz B-DRY waterproof/breathable membrane, molded rubber toe cap and heel kick Board lasted O FIT Insole Thermal Midsole: Dual density EVA, TPU chassis, nylon shank Outsole: Granite Peak with Winterized Rubber