Ever get the feeling you've been overlooked? Shazam. Never again. The Aireator is the original airflow design that changed how modern endurance socks are made. With its trademark venting mesh weave foot, durable 6" StayFast cuff, and durable heel and toe, the Aireator guarantees long-lasting performance. Made with CoolMax(R) EcoMade?, from recycled resources.Composition: 60% Nylon, 39% COOLMAX EcoMade, 1% Lycra. Sizing: Small (Women 6-8); Medium (Men 7-9 / Women 8.5-10.5); Large (Men 9.5-11.5 / Women 11-13); Extra-Large (Men 12+).