Only the originals will doyet again the original ultimate thermal sock adds to its wide range of warm choices with our new sockshop twisted yarn heat holders thermal socks these officially tested 23 tog rating socks are every bit as comfortable every bit as cosy as always but now with a good looking two shade marled effect a plain band cuff and a roll edge people from all walks of life love heat holders for their soft cosseting feel with a special blend of advanced insulating fibres