The inclusion of Thorlon fiber, toe cushioning, and arch support all work together to create a sock that addresses the specific needs of runners. Fiber content: 80% THOR•LON® acrylic, 19% nylon, 1% elastic. These socks are meticulously engineered to provide maximum protection and comfort in the critical strike zones, making them an ideal choice for runners who are susceptible to blisters, foot pain, or discomfort during their runs. Made with Thorlon fiber for super softness, durability and moisture wicking for drier and cooler feet.