EcoSox socks are socks woven from bamboo viscose fibers * Satisfaction/Blister Free Guarantee * Enhanced Moisture Control, Odor Control, Blister Resistance, and Thermo-Regulation * Ultra-Soft EcoSox Foot Bed Construction * Knitted Heel * Smooth Toe Technology * Full Crew Length * Arch Support * Stay Up Top * No use of additives and conditioners often used on other socks to give them the same properties. * Made in USA