This version of the classic Caribou has the same waterproof construction, full-grain leather upper and iconic silhouette you know and love, but comes with a wool inner boot instead of felt to keep feet warm, dry and cozy during activities in winter weather. Seam-sealed waterproof construction. Weight 964g (size 37, US 6) Dimensions (Size 37, US 6) Shaft Height: 23cm (9") Heel Height: 2.5cm (1") Calf Circumference: 43cm (17") Weight: 964 g (34 oz) Temperature rating (lowest): -40 °C Note! The shoes are designed to be functional in -40 degrees. This rating is different from user's comfort limit which is individual. Materials Upper: Waterproof nubuck leather Insulation: Removable 9 mm washable recycled felt inner boot with Sherpa pile snow cuff Midsole: 2.5mm bonded felt frost plug Shell: Handcrafted waterproof vulcanized rubber with SorelAeroTracnon-loading outsole