ECHOGORGE Expedition Heavy Weight Merino Wool Hiking Socks Made in USA Merino heavy weight wool hiking socks for maximum comfort, temperature control, and softness Medium fits US Men's shoes size 4.5-8.5 and US Women's shoe sizes 6-9; Large fits US Men's shoes size 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 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