Features of Smartwool Men's Run Zero Cushion Low Ankle Sock 4 Degree elite Fit system for a dialled-in, Performance-oriented Fit Mesh zones for added breathability Shred Shield Technology reduces wear from toes Virtually seamless toe for enhanced comfort Achilles tab prevents sock from slipping into footwear Height: Low ankle Zero cushion Fabric Details 53% Merino Wool 13% Nylon 30% Recycled Nylon 4% Elastane 53% Merino Wool 13% Nylon 30% Recycled Nylon 4% Elastane