Teko Women's M3RINO.XC Lightweight Merino Wool Casual Walking and Hiking Socks 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