Heat Holders - Mens Long Sleeve Thermal Top and Long Johns Set This Heat Holders set of thermal underwear is the perfect set for layering as of its easily fitting design for under your clothes for a smooth slim fitting thermal base layer for the colder days where one layer isn’t enough This thermal underwear set has a TOG rating of 0.39 adding that crucial extra layer of warmth. The higher the TOG the better the garment will keep you warm. They also have Heat Holders Thermal construction which holds more warm air close to the skin keeping you warmer for longer. The thermal underwear set includes a long sleeve thermal top, pair of long johns and comes in 2 colours: Charcoal or White. Available in 4 size options: Medium, Large, X-Large and XX-Large. They are made from: 53% Polyester, 47% Cotton and they are Machine Washable. Extra Product Details Heat Holders Men’s Thermal Underwear Set - Long Sleeve Top and Long Johns - Smooth and Slim Fitting - Thermal TOG Rating: 0.39 - Soft and Seamless Body - Available In Charcoal Or White - Heat Holders Thermal Construction - Hardly Noticeable Under Your Clothing - Perfect For Winter - 4 Size Options: M, L, XL and XXL - Machine Washable