A NEW AND IMPROVED DESIGN FOR ADDED DURABILITY - THE SMARTWOOL PHD RUN ULTRA LIGHT STRIPED MICRO SOCK. These socks have been newly redesigned to give you even more durability and comfort. The Smartwool PhD Run Ultra Light Striped Micro Sock features a Virtually SeamlessGao toe to prevent irritation as you're trekking along, and the IndestructawoolGao technology means these socks can keep going for miles on end without wearing out. The Shred Shield technology protects the socks from wear and tear, and the mesh zones keep you cool, dry, and happy. FEATURESIndestructawoolGao technology for enhanced durability4 DegreeGao elite fit system for a dialed, performance-oriented fitShred Shield technology reduces wear from toesBody-mapped mesh zones for added breathabilityVirtually SeamlessGao toe for enhanced comfortAchilles tab designed to prevent sock from slipping down into footwearTECH SPECSNo Show49% Merino Wool, 47% Nylon, 4% Elastane