The Darn Tough No Show topless sock quietly delivers the things that matter most-undeniable comfort, durability and fit. It is made of 54% Merino Wool, 43% Nylon and 3% Lycra® Spandex. The merino wool ensures breathability and comfort in all conditions. The sock pulls moisture away from skin and repels bacteria and odor. The sock has an undetectable seam fusion which gives ultra smooth, invisible feel.