KEEN Men's Daily Crew Lite Socks, Charcoal/Black, X-Large merino-wool 60% Merino Wool, 35% Nylon, 3% Lycra Spandex, 2% Polyester Left and Right design for optimal fit Seamless toe in flex zone to avoid bunching Machine wash warm inside out, Tumble dry low, Do not use fabric softner or chlorine bleach USA