Womens Boot Socks by Heat Holders Knee High Thick Thermal Socks These socks have the same warmth as the original Heat Holders® sock, but in an extra long leg length. These work really well with rubber boots and great for spending time outdoors during the cold winter months. Having the warmth of our original socks and the length of our extra long socks these have the added bonus of a turn over top to keep them in place over riding boots wellington boots or just longer boots. While keeping you warm and add some style to your wellingtons! What makes Heat Holders so warm? Our Specially developed thermal yarn provides high performance insulation against cold with superior moisture breathing abilities. Innovative knitting technology produces our unique extra long looped cushion pile to hold in more warm air increasing the TOG rating. Heat Holders are Scientifically tested to be over 7x warmer than a basic cotton sock! Heat Holders Tog rating being 2.34 whilst a basic cotton sock only measures at 0.33 Tog. Finally our expert brushing process maximises the amount of warm air held inside each sock for total warmth and all day comfort.