Credo Pop Art Sapphire Folding Nail File in Green is professional quality with added fun! The sapphire grains are fixed in the electroplating process on a spring steel blade for eternity. The chrome-plated surface allows the nail dust that occurs when the file falls out easily from the gaps of sapphire grains and the file surface always remains clean. In a strenuous process, a fine and a rough file side occurs. Perfectly ground and then hand-polished file edges ensure a smooth filing without damaging the nail bed by external sapphire cores. Always use the sapphire file in one direction and avoid movement to avoid emitting the nail edges.