The Run is part of our new ECO product line engineered with recycled yarns! Made using Repreve® recycled polyester yarn, this exciting product is amazingly comfortable AND sustainable. It’s a breathable lightweight+ Double Layer sock and is designed for a low profile performance fit. Ideal for running and walking. Over 2 plastic bottles used in each pair! Over 2 plastic bottles used in each pair of socks Repreve® Recycled Polyester inner and outer layers Stabilizer Zone™ in arch locks sock in place High needle count for added durability Certified, Sustainable, and Blister-Free socks - No Blisters, Guaranteed! Fiber ContentInner Layer: 70% Repreve® Polyester, 26% Nylon, 4% Lycra®Outer Layer: 68% Repreve® Polyester, 24% Nylon, 8% Lycra®