Men's Smartwool Phd Run Light Elite Micro - Black - Socks Turn the heat up on the pavement, and not in your shoes, when you gear up for your next run with this Smartwool running sock! Sold as a single-pair pack. Micro sock sits below the ankle. 200 needle construction provides high-density cushioning while maintaining light weight. Ultralight cushioning for optimal next-to-foot comfort without the added bulk. 4 DEGREE Elite Fit System employs two elastics for greater stretch and recovery. Strategically-placed mesh vents for temperature and moisture management. Achilles tab helps reduce the likelihood of irritation. Run-specific fit. 56% merino wool, 41% nylon, 3% elastane. Machine wash inside out on a warm, gentle cycle. Tumble dry low, lay flat, or line dry.