Arch brace holds the sock in place and adds additional support. Flat-knit toe seam keeps you comfortable throughout the day. Made in the USA of New Zealand ZqueTM Merino wool. * Light, half-cushioning is perfect for moderate hiking or aggressive walking. 76% merino wool, 23% nylon, 1% elastic. Washer and dryer friendly! * 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)