The women's Patagonia Capilene Air base layer bottoms insulate even when wet, dry quickly and resist odors, offering the greatest range of warmth and comfort of any Patagonia base layers. Fabric: 5.6 oz. 51% merino wool/49% recycled polyester Quick Drying Lightweight Capilene® Air is the most advanced base layer Patagonia has ever made; it feels light and soft on the skin and stretches naturally to move with the body in motion Fine merino wool from New Zealand is blended with Capilene recycled polyester for enhanced warmth, balanced with improved wicking, durability and dry time 18.5-micron-guage-yarns used in Capilene Air dramatically increases the yarn's loft while reducing weight compared to traditional wool yarn Seamless 3D construction eliminates chafe points through the entire garment and has almost no wasted material Elastic is seamlessly knit into a wide waistband for next-to-skin softness; a gender-specific zigzag knit texture to trap warmth and allow airflow