Seam-sealed, waterproof nubuck and suede leather.Built-in gaiter with barrel lock closure.Achilles adjustment strap.400g Thinsulate™ Ultra insulation.Removable 9mm EVA comfort footbed.EVA midsole inserts.Injection molded, waterproof thermal rubber shell.Rubber multi-directional lug outsole.Sorel Rated: -40°F / -40°C (yup, those temp conversions are correct.)