You can't have just one! This four-sided nail file shaper buffer and polisher is a must for the person on the go. Keep one at home one in your gym bag one for travel one in the car and hang on to a few to give as gifts. Use the deep charcoal side for filing the blue side for shaping the white side to smooth and the gray side for buffing and polishing your nails to a natural shiny finish. Comes in a vinyl sleeve so it won't snag on anything in your handbag.