The Smartwool Women's PhD Run Ultra Light Micro Sock is a minimal cushion sock for a close foot to shoe feel. Run connected to your shoe and the ground while the merino wool blend offers the moisture-wicking prowess and comfort to your skin. Trust in the 4 Degree Elite Fit System to stay put while flexing to keep ankle moving naturally. Mesh venting increase breathability and a Shred Shield up at the toes reduces wear when putting in the miles. Features of the Smartwool Women's PhD Run Ultra Light Micro Sock Indestructawool Technology for enhanced durability 4 Degree elite Fit system for a dialed, Performance-oriented Fit Shred Shield Technology reduces wear from toes Body mapped mesh zones for added breathability Virtually Seamless toe for enhanced comfort Achilles tab designed to prevent sock from slipping down into footwear Fabric Details 48% Merino Wool, 48% Nylon, 4% Elastane