Model Number:

With dense cushion pads under the forefoot and heel for protection and comfort, medium-weight Smartwool Men's PhD Running Light Micro Socks help you go the distance. Smartwool pairs merino wool with synthetic fibers in a snug, performance shape that's also durable; merino wool naturally wicks moisture to fight blisters and resists odor build-up.



  • Medium thickness, half-cushioned sock under heel and forefoot to absorb impact and increase comfort
  • 4Degree Elite Fit System combines 2 elastic types paired with wool for greater stretch that improves performance fit
  • ReliaWool Technology at High Density Impact Zones reduces shock and abrasions while increasing durability
  • Mesh zones for ventilation and comfort
  • Flat knit toe seam increases durability
  • SmartWool inside for natural moisture, temperature and odor control
  • Padded achilles tab for protection and secure fit
  • 1.75" tall low-cut


  • 71% Merino Wool / 27% Nylon / 2% Elastic

Sock Performance Characteristics

Sock Thickness What's this?

  • Extra Thin
  • Thin
  • Medium
  • Thick
  • Extra Thick

Sock Height What's this?

  • No Show
  • Low
  • Quarter
  • Crew
  • Knee High

Customer Reviews

Comments: I'm a huge Smartwool fan with thousand's of blister-free miles in my various Smartwool socks. The quality & comfort of this pair is as expected: Exceptional. One note, however, the difference between the Ultra Light & these as "Light" is significant in thickness/padding. I'd have named these medium. No matter the difference, they are comfy & great!
From: Aaron, Lincoln, NE, USA.  October 6th 2014

Comments: I love these socks! I don't get blisters in them! I run anything and everything in these. I have completed multiple half marathons, half iron distance triathlons, a marathon and trail runs in these. The only down side, besides the cost which they are wroth, is your feet get a little hot in them. I still wear them in the 100 degree heat in Oklahoma.
From: Russell, NM, USA. July 4th 2014