High-altitude mountaineering, Hiking, trekking Upper (instep): 58.2% polyester, 40.9% merino wool, 0.9% spandex(Excluding elastic components and decorative yarns) Breathable cotton feel for comfort and warmth Full terry padding for added foot comfort Air channel design for efficient moisture and heat wicking Elastic grip at arch and ankle to prevent shifting Wool-blend yarn offers both warmth and natural odor resistance