EchoGorge Premium Comfort Merino Wool Mid-Weight Performance Outdoor Socks - Made in USA Merino wool hiking socks for maximum comfort, temperature control, and softness Contents: 71% Merino Wool, 19% Nylon, 6% Acrylic, 4% Rubber Machine wash warm, no bleach, tumble dry low Arch comfort support and reinforced toe and heel Medium fits US Men's shoe sizes 4.5-8.5 and US Women's shoe sizes 6-9 Large fits US Men's shoe sizes 8.5-12 and US Women's shoe sizes 9-13.5 X-Large fits US Men's shoe sizes 12-15 and US Women's shoe sizes 13.5-16.5