54% US Nylon 43% US Merino Wool 3% US LYCRA Spandex Made in USA U.S. Merino Wool: Merino wool is soft, itch-free, naturally odor- and bacteria-resistant, cool in the summer and warm in winter. We source our 100% U.S. grown merino wool exclusively from sheep raised by American farmers on American farms. Hidden Nylon Plaiting: Advanced construction that sandwiches stretch yarns between two layers of body yarn, hidden nylon plaiting creates a smooth exterior and a low-profile fit that is ideal for technical and sport socks. A side benefit of this modern knitting technique is its ability to incorporate complex patterns, open-weave zones, and intricate designs for increased performance and extra style. Targeted Cushion Zone: Found primarily in our Snow Sport and Technical Hike series, targeted cushioning adds shock-absorbing loop knit at key impact areas of foot, shin & calf depending on designed use. Targeted cushioning helps reduce impact from activities like skiing and hiking while providing a better fit for ski boots and low-volume shoes. Full-Density Cushioning: Full-density cushioning features a terry knit loop on every interior stitch, providing better insulation, exceptional wicking, and increased protection against impact. Its faster moisture absorption keeps the skin dry and reduces friction, while its shock-absorbing nature enhances the performance of multi-sport and outdoor socks. Seamless Toe Closure: Advanced knitting techniques create a totally flat connection in the toe box, reducing bulk and eliminating blister-generating friction.