98% cotton 2% lycra. Elastic woven into top inch of ankle to help them stay up, lycra portion is not tight. Available in Big Foot and Small Foot sizes. Model has size 10 feet in women's shoe sizing and wears our Big Foot socks. Big Foot = women's shoe size 10 and up. Men's shoe size 9-12. Small Foot= women's up to a size 10 shoe. Men's shoe size 4-8.