Premium waterproof full-grain leather upper. Breathable waterproof membrane with moisture wicking mesh lining 400g PrimaLoft Gold Aerogel insulation Removable full cushion low density PU footbed. DuraSpring low density PU midsole resists compression for long-lasting comfort Sure footing with Vibram Arctic Grip outsole. ForgeTek direct-attach construction for durability and flexibility Nylon shank adds extra strength