The Women’s Merino Core Lightweight Bottom features premium 17.5-micron merino wool spun around a nylon core, creating a high-performance next-to-skin, all-season layer that combines the comfort, warmth, moisture management and natural odor control of wool with the durability and recoverability of nylon. The wide, yoga pant style waist and athletic fit maximizes comfort under heavy packs on your longest hunts.