The Darn Tough Pinnacle Micro Crew Charcoal features a sleek cuff that slides on smooth, along with the trail-rated toughness. The lightweight hiking men's sock features merino wool, fine gauge knitting, fast action wicking and true SeamlessT to offer an ultra smooth, invisible feel. The sock is guaranteed for life and is naturally antimicrobial. The micro crew height sock is light and strong with a versatile construction. It comprises of 50% nylon, 47% merino wool and 3% lycra?Â« spandex.