Only the originals will do! These super warm, super cosy Heat Holders thermal leggings have a soft brushed inside, which maximises the amount of warm air held close to the skin.  This thermal underwear is made from an advanced insulating yarn that provides high performance insulation against the cold. They also feature a comfort gusset which improves fit and adds comfort for all-day wear.These ladies leggings have a TOG rating of 0.39! What does ‘TOG RATING’ mean? Well, TOG is a recognised measure of a textile’s thermal ability. Simply put, the higher the TOG rating, the better a products is able to keep you warm. Copied by many. Equalled by none.(08/11)