This is it-the OG pac boot. The Kamik Nation Plus Pac Boots have been a top seller for years. Born in the trenches of WWII, built for service, worn by everyone since. Now, decades later, the Northern Plus Pac Boots have reborn lighter, tougher, grippier and better than ever. Classic synthetic rubber shell with suede/nylon uppers. Kamik's Heat-MX is their high-performance thermal insulation technology with built-in moisture-management that pulls sweat away from the foot to ensure internal dryness. Combined with their fleece lining, these boots will keep you warm down to a frosty -40degF/C. Underfoot is Kamik's GripXT, a specialized synthetic rubber outsole technology featuring deep, self-cleaning lugs designed to prevent snow and mud accumulation while maximizing traction in harsh winter and outdoor conditions. Suede with 600-denier nylon Synthetic rubber shell Fleece lining 145g Heat-MX sustainable, high-performance thermal insulation technology Waterproof seam-sealed Lace up Rated down to -40degF/C Removable liner Waterproof construction keeps your feet dry in the snow Grip XT special synthetic rubber outsole with deep, self-cleaning lugs