SmartWool Men's PhD Outdoor Heavy Crew Socks - Past Season 71% Merino Wool, 27% Nylon, 2% Elastane Knit in USA of Imported Yarn Built for Performance in the Highest Degree, Uses two elastics for greater stretch and recovery to keep the sock in place, Patented ReliaWool technology in high impact areas provides superior durability, Heavy cushioning offering significant impact absorption for extended backcountry excursions. Strategically placed mesh ventilation zones provide ventilation for temperature and moisture management Sock Height: Crew, 8.5" overall height Flat knit durable toe seam Style: SW0SW046