The Castelli Rosso Corsa Women's 11 Road Socks have a multiple-structure knit to get the right performance in every part of the sock.Castelli Rosso Corsa Women's 11 Road Socks FeaturesMultiple-structure knit to get the right performance in every part of the sock200-needle construction for extra stretchCompressive midfoot support bandAsymmetrical construction to mirror shape of footReflective tab at center backCushioning pad under ball of footMeryl® Skinlife yarns with antimicrobial silver ions to reduce odor