As the original air-flow design sock the Aerator is the sock that kicked off the air-flow rage years ago. Today the Aerator still leads in durability wicking drying and air permeability. Aerator stays cooler and more comfortable on your feet and lasts longer than anything else out there. That is why the Aerator remains the top pick of athletes competing at the highest level of sport.Contents: 60% Nylon, 39% Coolmax Eco-made, 1% Lycra ++++++++++++++++++++View the DeFeet sock sizing chart here