Dexshell Ultra Thin waterproof socks are the thinnest available. They are made from pulp, biodegradable Modal yarns, and bamboo rayon. They offer excellent comfort, flexibility, and breathability in warmer climates. Outer: 37% polyamide, 32% modal, 28% cotton, 3% elastane. Lining: Porelle membrane (100% polyurethane). Inner: 60% bamboo rayon (viscose), 40% polyamide. Thermal Guide 1