The same warmth and comfort as the original Heat Holders Crew sock, but with non-slip grippers on the bottom to provide better traction on indoor wood or tiled surfaces. Keep feet warm on the coldest of days and pull on this pair of slipper style, crew length Heat Holders for women (ladies), the warmest thermal sock. Thick, chunky and with a massive tog rating of 2.34, Heat Holders are made from a specially developed heavy bulk yarn which has extreme thermal qualities. With long pile cushioning, these thermal socks will help keep feet fully comfortable and supported. The inside of each sock has been intensively brushed that not only feels sensationally soft but also traps warm air close to the skin keeping your feet warmer for longer. Fiber Composition: 91% Acrylic, 5% Nylon, 3% Polyester, 1% Elastane.