WATERPROOF: The KEEN.DRY waterproof, breathable membrane keeps your feet dry and comfortable all day long by allowing vapor out without letting water in: All leather is treated with a PFC-free water repellant, so you still get the same protection without the harmful chemicals SUSTAINABILITY: Leather is sourced Leather Working Group (LWG)-certified tanneries: Tanned in the most environmentally way possible and is treated with PFC-free chemicals INSULATED: KEEN.WARM Recycled PET insulation helps keep feet warm in temperatures down to -40?? F / -40?? C, but still allows feet to breathe ODOR-PROTECTION: All KEEN products feature a natural, pesticide-free probiotic-based technology called Eco Anti-Odor technology for breaking down odor in sweat CARE TIPS: Gently brush the boot with a soft bristle brush or hand towel to remove loose dirt and debris: Treat stains by lightly rubbing a gum eraser in a circular motion over the location and lightly brush afterward