Smartwool PhD Outdoor Heavy OTC Socks

Size Chart

Smartwool's SW015047 PhD Outdoor Heavy Over the Calf sock is designed to deliver ultimate warmth. Now featuring Smartwool's Indestructawool technology for long-lasting durability. The 4 Degree Fit system will keep these socks comfortably in place. Premium Merino helps wick moisture, and keep feet dry. Like all Smartwool socks, the Outdoor Mountaineering sock is washer and dryer safe.


  • Over-the-Calf Height (14" overall height)
  • Heavy Full Cushion
  • Indestructawool technology features a wool-based, patent-pending yarn and construction method for exceptional durability and comfort
  • 4 Degree Elite Fit System for an all-day performance fit
  • Smartwool inside for moisture, temperature, and odor control
  • Ventilation designed for end use: more mesh in Ultra Light and Light weights ensures maximum breathability thermoregulation and moisture management
  • Virtually Seamless Toe
  • Washer and Dryer friendly
  • Made in the USA


74% Merino Wool, 24% Nylon, 2% Elastane

Sock Height

Knee-High Height Sock

Sock Cushion

Heavy Cushion Sock