Darn Tough Merino Wool Micro Crew Sock Cushion,Foliage Green,X-Small, 67% Merino Wool 29% Nylon 4% Lycra Spandex Merino wool is naturally flame resistant Naturally regulates body temperature Extreme wicking power and fast drying Machine wash them in warm water on gentle cycle with socks in-side out. Do not bleach. You can return this item for any reason and get a full refund: no shipping charges. The item must be returned in new and unused condition. Go to Your Orders to start the return Print the return shipping label Ship it!