Fiber Contents:?3%?Spandex , 70%?THORWICK COOL , 28%?Nylon Constructed with THORWICK COOL fibers for superior moisture-wicking for drier, cooler feet. Cushioned instep and arch for a better fit, more support and more comfort. Low profile toe seam won??t rub or irritate feet. Padding in the ball and heel absorbs shock and is specifically engineered for protection and comfort while running.