SmartWool PhD Ultralight Micro Running Socks - Ankle (For Men and Women)

Item #5851C
$7.99 Save 49% Compare at $15.95
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About SmartWool PhD Ultralight Micro Running Socks - Ankle (For Men and Women)

2nds. Utilizing an ultralight merino wool blend with ReliaWool Technology in high-density impact zones, SmartWool's PhD Running Ultralight Micro socks are designed for mild weather and shorter distances.


Specs about SmartWool PhD Ultralight Micro Running Socks - Ankle (For Men and Women)

  • Lightweight
  • Height: Ankle
  • Fabric: 54% merino wool, 42% nylon, 4% elastic or, 55% merino wool, 41% nylon, 4% elastic
  • Care: Machine wash/dry
  • Made in United States of America (yarn imported)
  • Visit our Wool Guide
  • US shipments only


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4.609090 5 Overall Rating: 4.6 Based on 110 reviews

Most Helpful 5-Star Review

Verified Buyer Reviewed by S from Virginia on Thursday, February 11, 2016
No sweat. No smell. And good price from STP. The only socks I wear. (Fact: You can wear them 3 or 4 times before washing and they STILL don't smell. Not that I tried or anything.)
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  • Verified Buyer Reviewed by Tireless Explorer from Colorado on Tuesday, January 31, 2017
    I wish SmartWool would hire me: not only because I really do have a PhD but because I am the biggest fan of their products, particularly their SmartWool PhD socks. I wear them all year long -- in the winter, they keep my feet at the perfect temperature; in the summer, they wick sweat. I have never experienced a single blister while wearing them. I wear these socks until they are virtually threadbare, and even then, I'll sometimes sew the small holes that form after miles and miles of running. Super high quality -- quite simply, no other sock can compare.
  • Verified Buyer Reviewed by Outdoorsman from Marin County on Tuesday, December 13, 2016
    My wife and middle school age daughter have used these socks daily for years and recently placed an order for more. They are among the best options available that are made mostly of wool, don't show above their shoes, and provide all day/all season comfort. Plus, the price is right at Sierra Trading Post and they are made in USA!
  • Verified Buyer Reviewed by Seth from Mexico on Tuesday, December 13, 2016
    SmartWool socks as great as ever! I can wear them for a jog or hike, then leave them to air out for a while and they'll be fresh to go again. STP gives the best price I've seen for this brand!
  • Verified Buyer Reviewed by Ridin' Dan from Colorado front range on Monday, December 5, 2016
    Bought this sock for cycling in the summer. Good fit, lightweight sock, comfortable, everything I could ask for in a sock
  • Reviewed by overhear from New York on Sunday, November 20, 2016
    I've worn smartwool PhDs for years, but these did not hold up like my older ones. After only 1-2 runs, my toes started to poke through the top of the socks. Then the bottoms began to fray. Oh well, guess I'll be looking for another brand.

Question & Answer

Questions about this product? Get answers from community and staff experts.

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  • “What reason are they seconds?”
    Asked by Tami from Arizona on 8/25/2016 10:45:50 AM
    • I have bought several pairs and use daily
      But can't tell why they are seconds
      Smart wool is a great product and maybe their expectations are really high to the untrained eye
      I can't see it
      Maybe if I knew what to look for
      Answered on 8/25/2016 10:51:51 AM by Ak ok from Alaska
    • We are not given exact reasons why products are being labeled as seconds. Generally it is due to minor cosmetic blemishes or irregularities which do not affect the fit, performance, or longevity of the item. Label is usually clipped by the manufacturer. A small flaw means big savings.
      Answered on 8/26/2016 8:34:49 AM by Product Specialist Greg from Sierra Trading Post
    • I see they've removed the sizing chart tab from some products. You can usually see the shoe size (7-9 1/2, 10-12 1/2, etc) a size (S, M, L) is intended for when you select a size (S, M, L). For this sock, for women, the Small should be for women's 4-6 1/2 and the Medium for 7-9 1/2.
      Answered on 12/13/2013 3:14:05 PM by Mel from Central New Jersey

About SmartWool

Born in the Rocky Mountains of Colorado, the SmartWool clothing brand launched in 1994 as a small company with roots in the snowsport industry. Quickly becoming world-famous for SmartWool socks crafted of super-soft, breathable and odor-resistant merino wool, SmartWool has continued to evolve, now offering a wide range of fantastic apparel for active lifestyles, including SmartWool ski socks, base layers, underwear, sweaters and even jackets. Thanks to a commitment to using only the highest quality fibers and sporty, modern designs, SmartWool socks and clothing continue to exceed the demands of outdoor lovers everywhere.