These are the thermal socks that are specially knit to retain heat, keeping feet seven times warmer than cotton socks. The socks' advanced insulating yarn is knitted with a unique tufted stitch into long-looped piles, and then the inside is intensely brushed to trap warm air closer to the skin while providing superior cushion and comfort. In independent laboratory tests, these socks achieved a Thermal Overall Grade rating (TOG) seven times higher than standard cotton socks and nearly three times higher than ordinary thermal socks. Plush and luxurious yet thin enough to wear comfortably inside boots or ice skates, the socks are also ideal for keeping feet warm while you sleep. 91% acrylic/5% nylon/3% polyester/1% elastane. One pair each of Black and Charcoal. (11 oz.)