Heat Holders - Womens Extra Long Knee High Colorful Winter Warm Thermal Socks 91% Acrylic, 5% Nylon, 3% Polyester, 1% Elastane Machine Washable 1 Pair of Ladies Heat Holders Long, in size 5-9 US. These have the great features of Heat Holders together with an extra long leg - keeping more of you warmer, for longer. Available in a range of stylish colours as well! Heat Holders Yarn - Our specially developed thermal yarn provides high performance insulation against cold with superior moisture breathing abilities. Heat Holders Loops - Innovative knitting technology produces our unique, extra long looped cushion pile to hold in more warm air, increasing the TOG rating. Heat Holders Brushing - Finally, our expert brushing process maximises the amount of warm air held inside each sock for total warmth and all day comfort. Heat Holders TOG Rating - These socks are scientifically tested to be 7X warmer than a basic cotton sock, with a massive tog rating of 2.3!