53% Nylon/39% Polyester/6% Cotton/2% Lycra Spandex. NB DRY moisture management technology quickly moves sweat to keep feet cool and dry. NB Fresh treatment with Silvadur keeps socks fresh and fights odors. Stability Fit built in for enhanced arch support. Stability fit arch support for a snug fit. Y-heel pocket keeps the sock firmly in place. Stability Fit Arch Support & Hold. Soft Touch Spun Polyester. Lightning Dry Moisture Management. Reinforced Heel & Toe. Anti-Microbial Finish to Fight Odor.