The Premium Aurora Crystal Nail File is made from quality crystal with European Etching Thermal Tempering Technology. The unique, gentle grit of the file allows for smoother filing and helps prevent chipping and breakage that usually occurs with regular nail files. The premium crystal material never wears out and is easy to disinfect. New Aurora colors are inspired by the natural phenomenon occurs in near Earth's poles and manifests as a dazzling display of dancing light. Instruction: 1. file in one direction and avoid filing in a back and forth motion. This reduces burrs that can occur with the sawing motion. 2. Start from the side of the nail and use one swift motion to file to the center of the nail 3. Repeat as needed until desired nail shape is achieved