Wigwam Women's Ironman Spectrum Pro Low Cut Merino Wool Running Sock 52% Stretch Nylon, 25% Polyester, 18% Merino Wool, 3% Lyocell, 2% Spandex Made in US Machine Wash Ultra-lightweight running and fitness socks using the patented Ultimax moisture control system enhanced with Merino Wool for year round performance Seamless toe closure and light cushioning at ball of foot to enhance comfort Merino Wool for softness and year round performance Lifetime Guarantee fashion colors