The Darn Tough Eclipse Lightweight Crew Black features chunky, graphic stripes that add a subtle pop to your look. The 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 crew height sock is built light, darn comfortable and super strong to provide a lightweight, sure fit. It comprises of 65% merino wool, 33% nylon and 2% lycra?Â« spandex.