The Smartwool PhD™ Outdoor Light Micro is made for the trail. The lightweight mid crew sock with Women's Specific Fit includes Indestructawool™ technology for ultimate durability, 4 Degree™ elite fit system for a dialed-in fit, and Virtually Seamless™ toe to offer extraordinary comfort in any trail shoe. The Mesh ventilation zones provide optimum moisture management and maximum breathability. It is made of 60% Merino Wool, 38% Nylon and 2% Elastane. All Smartwool socks are proudly made in the USA, and carry the Smartwool Promise.