Muck Boot Muckmaster Commercial Grade Rubber Work Boot Rubber Rubber sole 5 mm neoprene provides comfort and flexibility, along with excellent waterproofing, shock absorption and heat retention properties; adjusts to your foot shape to resist blisters and chafing Calf-high extended rubber overlay for increased moisture protection and puncture resistance; Stretch-fit Comfort Topline snugs calf to seal in warmth while keeping cold and debris out Breathable Airmesh lining wicks away humidity and perspiration, and allows air to travel throughout the boot EVA contoured molded midsole for added support; 2 mm thermal foam beneath the footbed for added warmth; comfort rated from -20 F/-30 C to 50 F/10 C 100% waterproof work boots; Rugged molded rubber outsole provides good traction on uneven outdoor terrain