Cushioned Terry Loop Crew Length Size is 9 - 11 Medium 75% Plush Acrylic or Cotton 20% Nylon, 5% Spandex A Great Sneaker Sock! Our cushioned socks are soft terry loop construction, which protects feet and reduces the shock of impact. They are engineered to provide protection against blisters and wicks away moisture to keep feet dry. Acrylic, the most widely used fiber for athletic socks is soft, washes well and holds its shape. Cotton is widely preferred for softness. Nylon is used for strength and spandex is great for stretching power. Perfect for hiking boots too.