The Darn Tough Number 2 Green men's sock provides long-lasting toughness and active comfort. The lightweight hiking men's sock features merino wool, fine gauge knitting, fast action wicking and a blown-out seam. The sock is guaranteed for life and is naturally antimicrobial. The micro crew height sock includes mid-level cushion density under foot. It comprises of 63% nylon, 35% merino wool and 2% lycra? spandex.