91% Polyester, 9% Elastane Machine Washable 1 pair of Heat Holders thermal tights, available in 4 sizes and colours! These tights are the best for thermal insulation against the cold. Advanced Insulating Yarn – High performance insulation against the cold, making sure you are your warmest even when it is freezing outside! Soft Brushed Inner – Maximises the amount of warm air held close to the skin, keeping you super warm for longer! 0.52 TOG – These have a massive 0.52 TOG rating – this is the measurement for thermal abilities, so you can be sure that these will keep you super warm. Improved Comfort – A comfort gusset and great stretch, means that these have the ultimate comfort when worn! They stretch you give the best fit to flatter your figure, and their comfort gusset means added comfort for all day wear.