Our elegant dichroic art-glass is designed and handcrafted in a magnitude of colors to bring out the natural beauty of the stone. The files are made of the finest, tempered Czech Republic crystal glass for lasting quality, strength and durability. All files are permanently etched, with filing surfaces on both sides. Frequent use reduces nail chipping and peeling. Easy to clean and sterilize with autoclave, UV lighting, alcohol, or hot soapy water. Dip in water for a flawless finish. Can be used on both natural and artificial nails. Dichroic or Elegance Collection files will NOT fit in the Hard Case File Protectors.