Thorlos Experia Unisex XWXU Multi-Sport Thin Padded Crew Sock 35% Merino Wool/31% Polyester/19% Nylon/14% Silk/1% Elastic Turn Inside Out-Machine Wash-Use Liquid Fabric Softner Specifically sculpted Thorlo padds in ball and heel provide protection from shear and impact Ultra lightweight sock frame of nylon and lycra provide aerodynamic contoured fit with mesh poly extra breathability Achillies Tendon Pad protects against rubbing and chafing