Durable hand-lasted rubber over a four-way stretch inner bootie. 7mm waterproof Neo-Techâ”¢ insulation for added comfort and warmth. Convenient pull handles provide a secure fit and easy on and off. Max-Wickâ”¢ moisture-wicking lining helps feet stay fresh. Dual-density, contoured EVA footbed features DuraFresh biotechnology to fight unwanted odors. Non-marking, non-slip rubber outsole with a self-cleaning tread. Comfort rated from temperate to -40Â°F/-40Â° (Yes, these temp ratings are correct).