The new and improved PhD Run Ultra Light Pattern Micro features Smartwool’s 4Degree™ Elite fit system, Indestructawool technology for superior durability, and a virtually seamless toe. Men's-specific mesh ventilation zones provide ultimate temperature and moisture regulation where male runners need it most.

• 45% Merino Wool/50% Nylon/5% Elastane
• PhD®: Built for Performance in the Highest Degree
• 4 Degree™ Elite Fit System: Uses two elastics for greater stretch and recovery to keep the sock in place
• Indestructawool™ technology features a patent-pending construction method for exceptional durability and comfort
• Men's-specific mesh ventilation zones provide additional breathability and moisture management
• Ultra Light Cushion: Minimal cushioning for maximum next-to-foot performance without added bulk
• Sock Height: Micro
• Virtually Seamless™ toe
• Achilles tab
• Made in USA of Imported Yarns