8 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 Soft fleece lining and 2 mm thermal foam under footbed enhances comfort, provides superior warmth, and is durable for long cold treks; comfort rated from -60 °F to 30 °F (-50 °C to -1 °C) Comfort topline keeps out moisture while locking in heat; EVA contoured, molded midsole for premium comfort; extended rubber coverage and tough Spandura adds protection against wear Vibram Arctic Grip outsole pods deliver the most advanced traction on wet ice; Vibram Icetrek full base layer provides the highest level of traction on dry ice 100% waterproof winter boots; multi-directional outsole lug design offers excellent traction on multi-surface terrain; rear pull loop for easy on/off