Love these socks! With 56% alpaca, 24% bamboo, 17% nylon, 3% microfiber, they can be worn all year long, not too hot in the summer and cozy all winter long. Superior wicking for dampness and odor. Low cut athletic sock features a cushioned & breathable mesh upper. Heel pad keeps the sock in place. Nylon reinforced heel and toe and a flat toe seam. Comes in grey, black and white. Medium Women’s 6 - 9 Men's 6 - 8.5 Large Women’s 9.5 - 12 Men's 9 - 12.5 Extra large Men's 13 - 16