Features of the Smartwool Women's PhD Cycle 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 Narrower heel and Slimmer Fit Fabric Details 46% Merino Wool, 50% Nylon, 4% Elastane