We teamed up with Smartwool athlete and ultrarunner Rob Krar to make a sock that can handle the longest trail runs. Introducing our PhD® Pro Endurance Krar Print Crew. This running sock features Indestructawool™ technology for enhanced durability, our Virtually Seamless™ toe for added comfort, and our 4 Degree™ elite fit system for a dialed, performance-oriented fit—so you can stay confident on the most rugged trails. And body-mapped mesh zones keep things breathable mile 1 to mile 100. Get ready to rack up more miles than ever before.
4 Degree™ Elite Fit System
For a dialed, performance-oriented fit with flex zone at ankle joint
Mesh ventilation zones provide optimum moisture management and maximum breathability
Shred Shield helps reduce wear from toes
Indestructawool™ technology features a patent-pending construction method for exceptional durability and comfort
The absolute minimum between you and your shoes.
Rob Krar signature sock
Indestructawool™ technology for enhanced durability
4 Degree™ elite fit system for a dialed-in, performance-oriented fit