From Darn Tough, these socks feature: Performance fit for no slipping/bunching/blisters Seamless toe Lightweight yarn Moisture-wicking, thermoregulating, anti-microbial 51% Merino wool / 45% nylon / 4% lycra spandex Care: Machine wash in cold water on gentle cycle with socks inside-out Tumble dry on low or hang dry Do not bleach Do not dry clean Made in the USA. Lightweight Micro Crew height socks, knit with climate-controlling Merino Wool and cozy cushion underfoot, and you'll be trekking on without fear of the dreaded swamp-foot that can lead to blisters.