5 mm neoprene provides comfort and flexibility along with excellent waterproofing shock absorption and heat retention properties adjusts to the shape of little feet to resist blisters and chafing Highgrade rubber exterior provides extra toughness and makes for a 100 waterproof snow boot Soft fleece lining provides superior warmth and comfort in extreme cold conditions comfort rated to 40 F to 40 F 40 C to 4 C EVA footbed for lightweight support and cushioning Aggressive durable outsole for better traction on ice and rainslick surfaces