The Arctic Sport Mid is our mid-height boot for extreme winter weather conditions. These boots step up the warmth factor with soft fleece lining and a 5mm neoprene inner boot for ultimate warmth in harsh cold conditions. The stretch-fit top-line binding keeps the boots snug to your legs to keep cold air out and warm air in, and provides the perfect fit for wide calves. As well as an EVA molded sole for supreme comfort, these high-performance sport boots feature an added 2mm thermal foam underlay for extra warmth. For those extra muddy or frozen days, the outsole is rugged, durable and offers ultimate protection with double reinforcement on the instep, heel and Achilles area. 100% Waterproof, 100% MUCKPROOF 2mm Thermal foam under the footbed for extra warmth 5mm Neoprene Bootie for Comfort and Performance Comfort Topline Lightweight Midsole for All Day Comfort and Support Pull tab for easy on/off Self-Cleaning MS-1 Lug Outsole is Excellent in Mud, Snow and Dirt Warm Lining: Soft, Insulation, Light-weight, Performance Materials for Warmth and Comfort