Men's Thermal Underwear Bottoms Heat Holders thermal construction holds more warm air close to the skin, keeping you warmer for longer. This 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 0.45, adding that crucial extra layer of warmth. The higher the TOG the better the garment will keep you warm. The ribbed construction of this thermal underwear has been designed so that it effortlessly shapes to the bodies natural contours - helping to provide the best fit possible making it hardly noticeable under your clothing. The base layer is made of a cotton-rich blend, which gives you the most natural softness and warmth for all-day wear. This bottoms part to the set has an elasticated waistband, meaning it has an ease of fit. The thermal underwear set comes in 2 colours (Grey and White), and there are matching tops also available in separate listings. We also offer women's sizes/colours. Extra Product Details - Thermal Long Johns - 4 Sizes - 2 Colours - Super soft & comfortable - Ribbed construction - Cotton Rich - Elastic Waistband - Extra warm - 0.45 TOG - Shirts also available