Sorel Men's Caribou Waterproof Winter Boots - Often imitated but never equaled, the original Sorel boot features a nubuck leather upper with waterproof construction, seam-sealing and a removable ThermoPlus(TM) felt inner boot for warmth, comfort and protection in cold and wet winter weather. Seam-sealed waterproof construction Removable 9mm ThermoPlus felt InnerBoot Sherpa Pile snow cuff Handcrafted waterproof vulcanized rubber shell with Sorel aero-trac non-loading outsole 2.5mm bonded felt frost plug Imported Style: NM1000