DeFeet Aireator 2.5 Socks Bike Black XL PairThe original air flow design sock Very thin sock without much cushion, excellent for use with close fit shoes Super light, low bulk, and fast drying Aireator mesh on top of sock helps air flow and keeps your feetcomfortable No slip cuff helps keep the sock up 60% Nylon, 39% CoolMax, 1% Lycra Made in USA TECH SPECS Color Bike Black Primary Color Black Fabric Technology Aireator mesh Cuff Height 2. 5 Size XL Core No Misc 35% Nylon 43% CoolMax 14% Lycra