Use:
TRIND Nail Magic Buffer is a file that smoothes the nail surface. It removes small ridges and uneven nail, leaving you with smooth and shiny nails. When using the buffer make semicircular movements. Start with the black side to remove the top layer of the nail (use this side only once every 4 weeks). Then use the white side, which stimulates the production of natural nail moisture. Lastly, you will distribute your nail’s own moisture by using the grey side of the buffer in the same manner for a shiny result.