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 Extended, soft rubber coverage; tough, flexible Spandura adds protection against wear; improved midsole for better support Soft fleece lining enhances comfort, provides superior warmth, and is durable for long cold treks; comfort rated from -40 °F to 40 °F (-40 °C to 4 °C) 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