100% waterproof - Built with seamless construction - making them lighter and more durable - Constructed with 5.5mm Yulex natural rubber waterproof insulation and 2mm of air mesh for temperature regulation - Boot shaft easily adjusts to fit different size calves - Self cleaning slip resistant BioGrip outsole - DuraFresh natural bio-technology activates to fight odors - Bio-based footbed provides comfort while minimizing environmental impact - Comfort rated -40F/-40C