6 layers of insulating warmth and protection! - DUREVA outsole blocks the cold for more warmth and comfort - 5.5 mm bootie; 2 mm airmesh; 2 mm warm fleece lining - Double achilles heel and instep reinforcement for comfort and protection - Adjustable Gusset Style - customize to fit larger calves for optimum - comfort and protection with our expandable gusset and adjustable - locking strap; Extra room also accommodates layers of clothing being - tucked into the boot; 2" taller than our regular model for extra protection - from the elements brush and debris