Teko M3RINO.XC Lightweight Hiking Socks for Men and Women, Storm, X-Large 71% Merino Wool / 28% Nylon / 1% Elastic Made in US 70% organic merino wool, 27% nylon, 3% Lycra Spandex Designed for hiking, backpacking, snowshoeing and cold-weather everyday wear. Organic, undyed, chlorine-free Merino wool is naturally wicking and insulating. Recommended for all weather conditions. Machine Washable Made In USA