Running Protection Level 3: designed to help protect your feet from the damaging effects of impact, shear and blistering common to running/jogging. Provides the most protection available (beyond what any other sock can provide today) and may require a 1/2 size larger shoe. Wear this product when fitted with new shoes. Heavyweight padding at ball and heel provides protection against shock, impact and shear forces. THOR-LON throughout the body of the sock wicks moisture, keeping feet drier and reducing blisters. Lightweight padding in arch provides protection and allows for better fit and arch support. No-sock sock sits below the ankle. Sold as a 3-pair pack. 71 percent polyester, 27 percent nylon, 2 percent elastic. Made in the USA.