Ultra soft, fine gauge Merino Wool makes them a year round, all weather favoritenTrue Seamless construction gives them a smooth, almost invisible feel from start to finishn49% Merino Wool, 48% Nylon, 3% Lycra SpandexnMenu0026#39;s Sizing Guide: Small (5.5-7.5), Medium (8-9.5), Large (10-12), X-Large (12.5+)nWomenu0026#39;s Sizing Guide: Small (4.5-7), Medium (7.5-9.5), Large (10-11.5)nDarn Tough's Ivy Knee High doesn't particularly care which way it goes, it just follows the sun. These women's lifestyle socks deliver legendary Darn Toughness and fashion to boot. Ultra soft, fine gauge Merino Wool make them a year round, all-weather favorite. Light, simple, and laid back. True Seamless construction gives them a smooth, almost invisible feel from start to finish. Pure Bliss. Still made in Vermont. Guaranteed for life.