This Smartwool PhD Run Ultra Light Low Cut 3-Pack of running socks will have you burning up the miles in pursuit of your next milestone. Low socks that sit at the ankle. Sold as one-pair pack. The PhD socks are packed with technologies that are designed to keep your feet comfy so you can focus more on the trail. 4-Degree Elite Fit System construction uses two elastics to provide better stretch and to keep your sock in place. Indestructawool is engineered to provide maximum comfort and durability. Mesh panels on the out step help provide added breathability. Shred Shield reduces wear and tear on the toes for added durability. Ultra-light cushioning provides maximum performance with minimal cushioning to works well in close-fitted shoes. Virtually Seamless toe is designed for all day comfort and to minimize chaffing. Style Number: SW000659 48 percent wool, 47 percent nylon, 5 percent elastane. Machine wash, tumble dry. Made in the USA.