The Assos RSR Socks S11 use InfraRed yarns with a high concentration of elastomer, blended with Lycra, for firm, graduated support through the foot, ankle, and lower leg. A 240-needle seamless knit removes friction points along the foot for a low-profile fit inside a cycling shoe. The compression sits at 25mmHg, firmer than a standard riding sock, engineered for long stretches of high-intensity effort. What Our Gearhead® Experts Are Saying:"I've worn these through five-hour rides in ninety-degree heat and my feet never got that swampy, overheated feeling I get in a heavier sock. The compression stays firm mile after mile instead of going slack once things get sweaty."