Chestnut Run Training Low Ankle Socks - Men. Purpose-driven sock with performance features to help you churn out those miles. Features - Targeted Cushion Indestructawool technology with extended durability zones4 Degree elite fit system for a dialed-in, performance-oriented fit - Mesh zones for added breathability Virtually Seamless toe for enhanced comfort - Achilles tab prevents sock from slipping into footwear - Product details54% merino wool / 41% nylon / 3% elastane / 2% recycled nylon Machine wash - Knit in the USA with imported yarn