48% Polyester/21% Nylon/15% Acrylic/15% Wool/1% Lycra Spandex. Made in US NB DRY moisture management technology quickly moves sweat to keep feet cool and dry. Stability Fit built in for enhanced arch support. Cupron antifungal fibers in heel and toe are EPA registered to kill 99.9% of Athlete's foot fungus after 12 hours of contact with socks. Strategic cushioning around heel and toe helps with shock absorption. Reinforced heel and toe for added durability. Breathable mesh panels promote airflow to keep feet feeling dry and cool. Reinforced heel and toe for extra durability and protection.