Alloy Fibre Heating ElementThe durable and flexible alloy fibre heating element in these socks gently warms your foot from the toes - the part of the foot most susceptible to cold. The socks are made from a high quality, wool-rich material that helps to keep feet warm even when the socks are turned off. The inside of the sock is thick, soft, and springy, making the socks comfortable and snug. The cuff is soft and stretchy, providing a better fit and preventing heat from escaping. These insulating features help to keep the heat where you need it most, and the stretchy cuff helps to stop the socks from slipping down.