SmartWool Men's PhD Outdoor Ultra Light Mini Socks - Past Season 53% Merino Wool, 42% Nylon, 5% Elastane 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, Minimal cushioning for maximum performance in close-fitting shoes Strategically placed mesh ventilation zones provide ventilation for temperature and moisture management Sock Height: Mini, 3.75" overall height Virtually seamless toe Style: SW0SW040