Heat Holders - Mens Thick 2.3 TOG Non Skid Thermal Slipper Socks with Grippers 91% Acrylic, 5% Polyamide, 3% Polyester, 1% Elastane Machine Washable Heat Holders Slipper Sock - All the greatness of Heat Holders, but with a anti-slip sole! Making it safer to walk around on slippy home flooring such as wood, laminate or tiles. Heat Holders Yarn  Specially developed thermal yarn provides high performance insulation against cold with superior moisture breathing abilities. Heat Holders Brushing - Finally, our expert brushing process maximizes the amount of warm air held inside each sock for total warmth and all day comfort. 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 TOG Rating - These socks are scientifically tested to be 7X warmer than a basic cotton sock, with a massive tog rating of 2.3!