SmartWool PhD Nordic Light Elite Socks 53% Merino Wool, 43% Nylon, 4% Elastane Knit in USA 200 needle construction provides highest knit density while maintaining ultra light weight Virtually Seamless toe Sock Height: Crew - 8.5" overall height Style: SW015060 Care: Machine Wash Warm Gentle Cycle. Do Not Bleach. Tumble Dry Low. Do Not Iron. Do Not Dry Clean.