GelStep® heel cups are made from 100% medical-grade silicone. Specifically designed to absorb shock, relieve pressure and cushion heels to ease pain. ‘Blue Zone’ Comfort Spots feature softer Silicone for extra protection in high-impact areas. This dual-durometer design provides maximum comfort and cushioning. Available uncovered or with an odor-control, anti-microbial top cover to help absorb perspiration, reduce friction and improve comfort.