Our superwash wool long underwear are made with a 1x1 rib fabric that uses unique yarns to create a comfortable and warm wool garment. Nylon has been added to improve the durability and extend the life of the garment. Featuring a double seat for warmth, reinforced cuffs with spandex for comfort and shape retention, leg gussets give thighs extra room for a proper fit, and our plush back signature elastic waistband.