Sockwell Women's Tempest Socks 33% Merino Wool, 33% Bamboo Rayon, 29% Stretch Nylon, 5% Spandex Made in US Turn welt top helps keeps the sock in place Spandex throughout the sock prevents slippage and ensures a snappy fit throughout the day Ultra flat toe seam for superior in shoe comfort Non cushion sole Y Heel shape design for better fit