Most thermal socks with merino wool have 50 to 60% merino, while ours have 80%. More merino means more warmth and comfort from the finest wool material. These socks are even softer on the inside, with brushed fleece linings at the feet. This makes them great for cold weather outdoor activities, as well as lounging around the house. Don't get cold feet in cold weather -get 80% merino wool socks!