Durable nylon uppers are coated with polyurethane to resist wind and water, helping lower legs stay dry and warm; molded rubber shells keep snow and water outDrawstrings with cordlocks cinch collars snugly around lower legs to keep snow out; fixed elastic instep straps secure feet comfortablyRemovable 6mm liner boots are made of recycled polyester and polypropyleneExtra insulation from 2.5mm bonded felt frost plug insolesSorel Cub winter boots sport rubber outsoles with muddy proof lug