From Darn Tough, these socks feature: Performance fit Chafe-eliminating cuffs Cushioned heel tabs offer extra protection behind the heel from friction and keep debris at bay Soft-cushioning underfoot Runners enjoy Merino Wool's ability to dry quickly and move excess heat and moisture away from fee Antimicrobial One size fits most men's shoe sizes 9-13 lightweight nylon/Merino wool/Lycra® spandex Machine wash/tumble dry Made in the USA.