Merino Wool is a natural wonder that is soft, warm, and naturally moisture-wicking to keep your feet dry and cozy. We blended it with polyester and spandex to create a magical yarn that helps create a perfect fit that offers just the right amount of stretch, tension, and arch support. While originally made for winter days, we've seen a big increase in Bombas fans wearing all of our merino styles year round. Women's Merino Wool Blend Knee-High Socks - Ink Black - Medium - Bombas