Inner Layer: 70% REPREVE Polyester, 26% Nylon, 4% Lycra / Outer Layer: 71% REPREVE Polyester, 24% Nylon, 5% Lycra Machine Wash Blister-Free socks - No Blisters, Guaranteed! Mesh panel for enhanced air flow and cooler feet creating breathable socks you can comfortably wear all day. Repreve performance fibers improve moisture management and increased durability creating socks that will last Stabilizer Zone in arch locks sock in place to reduce socks slipping throughout the day For optimal performance, launder before wearing. Machine wash warm, inside out. Do not bleach or use liquid fabric softeners. Tumble dry, no heat. The Coolmeshll is our #1 selling sock worldwide! It’s the most breathable lightweight Double Layer sock and is designed for a minimal feel. Ideal as running socks, walking socks, or light hiking socks, the Wrightsock Coolmesh II Quarter Socks work to prevent blisters while remaining one of the most lightweight and breathable socks on the market. The The Coolmeshll are great travel socks that dry quickly and are ready for use the next morning. So whether you are hiking a new mountain, running a new route, or walking through a new city, Coolmeshll socks will keep you dry and blister-free all day long.