Our double knit socks have been made in Japan for over 30 years. Double knit means more design variety and greater strength and comfort on the foot. Very few of these machines exist in the world. Double knitting uses two cylinders which means longer production time and requires skilled engineers. Content is 70% Cotton, 30% Nylon. Made in Japan. Shoe size 9-12. Care Instructions: Machine washable in lukewarm water delicate. It would be best to not put them in the dryer, but if you do, make sure it is on the lowest temperature possible or on "fluff" dry.