The "original airflow design sock" combines the wicking capabilities of CoolMax EcoMade with the abrasion resistance of nylon, so your feet stay cool and comfortable during activity. The DeFeet Aireator Spotty Hi-Vis Socks have a 4" single-layer cuff with a fresh palette of highly visible colors. Wide mesh weave Aireator upper is highly breathable and quick-drying. Super light and thin design fits perfectly inside your bike shoes. Super light and thin design fits perfectly inside your bike shoes.