Wise Hunters Heated Wool Blend Extra-Long Pocket Socks are made of 50% Merino wool, 25% acrylic, 17% Polypropylene and 8% Lycra spandex. This over the knee sock has pockets over the toes to hold HotHands Foot-Warm-Ups (free with each pair). These socks have the unique compression fitting designed to keep socks up and to improve circulation in the legs. And best of all they're MADE IN THE USA.