87% Nylon, 13% Spandex; Latex-Free Imported TOP QUALITY: The fibers in Microfiber Shades are innovative in the sense that they enhance performance and durability. We use high-filament synthetics and channeled polyesters which wick away moisture HIGH STANDARDS: All Sigvaris products are listed as Class 1(general edema) and Class 2(blood flow) with the FDA. Along with being ISO(International Organization for Standardization) certified, this proves that our products truly benefit customers. ORIGIN: Born in Switzerland. Made in the USA. People buy and wear compression garments for the prevention and treatment of certain issues, such as leg comfort and prevention of DVT during long-distance travel and the treatment of leg swelling and vein issues. SIZING: Our knitting machines regulate stitch length and yarn tension while shaping the fabric to a leg model for the best fit. The compression level of these socks is 15-20mmHg, which was crafted with the most precise sizing chart in the industry. MATERIALS MATTER: Every single one of our products is made of natural and synthetic fibers and contains no animal products. Made of 87% Nylon, 13% Spandex; Latex-Free, Sigvaris makes products that are effective, durable, and of the highest quality.