This is a warm, light and incredibly soft underwear for men from Tufte, made from 100% super fine merino wool. In other words, very soft. Dress in layers with this on the inside for good warmth on cold days. Perfect under a pair of coveralls or hiking pants on a cold day.The natural and wonderful properties of wool will keep you warm even if you get wet or sweaty, and it is temperature regulating so you are warm in the cold and cool in the heat. In addition, wool is naturally renewable, recyclable and degradable.