Lozonstar Electric Nail File & Callus RollerSimply change the head to easily care for your heel calluses and nail care with "file and polish." 1. "Calling head" Formulated with diamond powder, known as the hardest callus remover, it quickly removes hardened calluses, leaving your heels smooth. 2. "Electric nail file" Simply place it on your outgrown nails! No force required, comfortable and safe. Even hard nails on your hands and feet are filed, not cut, for a beautiful finish with a natural