Wigwam Women's Ironman Lightning Pro Low Cut Running Sock 3-Pack 42% Nylon, 32% Lyocell, 22% Acrylic, 2% Polyester, 2% Spandex Made in US Machine Wash Made in USA Features the ultimax moisture control system to protect against blisters and odor Ultralight weight running sock Dri release fabrication enhances odor and blister protection Unique heel tab reduces the chance of sock slippage into the shoe