KEEN Women's Olympus Medium Crew Socks, Gray, Medium 53% Wool/30% Nylon/9% Polyester/6% Dyneema Polyethylene/2% Lycra Spandex Made in US Contour arch support for comfort Dura-zone high-tenancity nylon fibers Left and right design for optimal fit Seamless toe in flex zone to avoid bunching Engineered comfort, classic hiking sock with double layer construction