AngelFeet files are etched out of a single piece of surgical-grade stainless steel to create thousands of pyramids into a pattern to safely remove dry, cracked, and calloused skin. This technology makes the pedicure fast, safe, and easy to use without cutting or grating the skin. Each file is double-sided. One side is rough for hard cracked, and calloused skin, and the other is for not-so-rough skin. You get the same Fine abrasive side with each file to accommodate softness.