SmartWool Walk Light Crew Socks 60% Merino Wool, 38% Nylon, 2% Elastane Knit in USA Smartwool Fit System with arch and ankle support helps keep sock in place Waffle Knit Flex Zone Flat knit toe seam - Reinforced sole Style: SW0SW250 Care: Machine Wash Warm Gentle Cycle. Do Not Bleach. Tumble Dry Low. Do Not Iron. Do Not Dry Clean.