This Darn Tough Steely 1/4 Midweight sock combines the perfect blend of spandex, nylon and merino wool for ultimate comfort and durability. The fast action wicking pulls moisture away from the skin for a cool, dry feel all year round. Plus, it has an undetectable seam fusion for an ultra-smooth, invisible feel. And with their lifetime pledge to replace any socks that wear, tear or develop holes, you can be sure these socks will last a long time! Investing in this quality midweight cushion sock is a great way to keep your feet comfortable and protected no matter what outdoor activity you're enjoying.