Thorlos Experia Unisex XCXU Multi-Sport Thin Padded Crew Sock 74% Thor-Wick COOL polyester/14% Polyester/10% Nylon/2% Elastic Made in US Turn Inside Out-Machine Wash-Use Liquid Fabric Softner Sculpted pads in the ball and heel provide protection from sheer and impact in critical strike and impact zones Achilles tendon pad protects against rubbing and chafing while functioning as a heel lock