Smartwool's PhD Outdoor Medium features Reliawool™ Technology for improved durability in the high wear areas and the 4-Degree Elite Fit System, to keep the sock in place and giving you all-sport versatility.
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
Patented ReliaWool™ technology in high impact areas provides superior durability
Medium cushioning to absorb impact on the trail