Heat Holders Men's Original 2.3 tog winter Thermal Socks 7-12 US 91% acrylic, 5% nylon, 3% poly, 1% elastane Machine washable Advanced Insulating Yarn - Our specially developed advanced fibres provide high performance insulation against cold with superior moisture breathing abilities. Extra Long Looped Pile - Innovative knitting technology produces our unique, extra long looped cushion pile to hold in more warm air, increasing the thermal tog rating! Expert Brushed Inner - Finally, our expert brushing process maximizes the amount of warm air held inside each sock for total warmth and all-day comfort. Over 7x warmer than a basic cotton sock - A basic cotton sock is usually tog rated at 0.33 tog, and any ordinary thermal sock is only 0.89 - Heat Holders reach to 2.34 tog! Choose from over 30+ colors in our mens heat holders range, also available in sizes 13-15 US as well as 7-12 US.