Using trusted Smartwool technology, these advanced low ankle running socks offer maximum comfort with minimal bulk. In a blend of 56% merino wool, 41% nylon and 3% elastane. Achilles tab designed to prevent sock from slipping down into footwear. Mesh ventilation zones provide optimum moisture management and maximum breathability. Targeted cushioning in the ball and heel of the foot for ultimate shock absorption. Virtually Seamless toe for enhanced comfort. Indestructawool technology for exceptional durability. Made in USA of imported materials.