This is a high quality product made in the USA The foot is made of 90% Merino Wool + 10% Nylon, the leg 60% acrylic, 20% Merino wool, 17% nylon, and 3% spandex. This is a heavyweight sock designed for extreme climates The fully cushioned leg and foot is designed to absorb shock while the merino wool keeps the foot dry and warm Merino wool is naturally antimicrobial The heel and toe are reinforced and have a flat toe seam for ultimate comfort and longer sock life The leg features a special stay up leg and top.