Smartwool Men's PhD Run UltraLight Micro
PhD Run Ultra Light Micro sock with patent pending ReliaWool Technology. Also features 4-Degree Fit System, keeping the sock in place and giving you all-sport versatility. Flat knit durable toe seam for high burst strenght. Men's sock sizes - Medium (fits US shoe size 6-8.5) Large (fits US shoe size 9-11.5) X-Large (fits US shoe size 12-14.5). Women's sock sizes Small (shoe size 4-6.5) Medium (shoe size 7-9.5) Large (shoe size 10-12.5)