I love these pants & live in them all winter. People who work out doors in the winter wear these as long underwear, (roofers swear by them), my Mother sells them everywhere she goes,  & my 5 sisters and father all have at least one pair. This Polartec®  Powerstretch® is brushed on the inside and left smooth on the right side. What more can I say? Simple elastic waist for an exceptionally comfortable fit. Men's Sizes: S-XXL.