SmartWool PhD Outdoor Heavy Over The Calf Socks - Past Season 74% Merino Wool, 24% Nylon, 2% Elastane Made 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 Flat knit durable toe seam Sock Height: Over the Calf, 14" overall height Style: SW0SW047