DeFeet Size Chart The original DeFeet sock, the Aireator has been consistently upgraded and remains the gold standard of cycling socks. Affordable and incredibly durable, Aireator's are the most popular cycling sock the world has ever known. Features: - DeFeet Aireator mesh for superior breathability and comfort, the first sock to incorporate this type of open-mesh construction. - Eco-friendly: Made from recycled water bottles in North Carolina, USA. - Great for running, hiking, and on the bike - Machine wash cold, tumble dry low. No bleach, softeners, or harsh detergents. - 60% Nylon, 39% Recycled Polyester, 1% Lycra