KEEN Men's Bellingham Crew Lite Socks, Black/Black, Large 52% Wool/ 41% Nylon/ 5% Polyester/ 2% Spandex Made in US Y heel pockets for better fit, arch support, and Seamless Anatomical Flex Fit system reduces bunching under foot Merino wool regulates temperature and wicks moisture from skin Ravel-free double welt top keeps socks up Engineered comfort, classic hiking sock with double layer construction