- The primary materials that compose this product contain a minimum of 20 percent recycled content. - When you need that little extra comfort and warmth on your adventurous outdoor trips, reach for the Smartwool® Run Zero Cushion Ankle Socks. - Sold as a 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. - Ultra-light cushioning provides maximum performance with minimal cushioning to work well in close-fitted shoes. - 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. - Shred Shield™ reduces wear and tear on the toes for added durability. - Achilles strap helps give you added protection and warmth. - Mesh panels on the out step help provide added breathability. - Merino fibers provide outstanding softness and construction. - Sits at the ankle length. - 46% Merino wool, 26% nylon, 25% recycled nylon, 3% elastane. - Machine wash, tumble dry. - Made in the USA.