Material: 93% acrylic/6% polyester/1% spandex.Machine wash cold with like colors, tumble dry low Warm enough for winer and extreme cold weather.3 x warmer than cotton, great for sports, hiking, skiing and other outdoor activities. Comfort – You deserve comfortable socks and these are them. Just feel the inside of these warm brushed lined socks. Size Medium for mens shoe size 6.5-9/women shoe size 7-10, size large for men shoe size 9-12. Package: Include 2 pairs thermal socks.