The Edge Duraboard Curved 240/240 Grit File (x 10) is a softer, finer grit double sided file that can be used on natural nails. It is ideal for finishing the nail e.g. buffing for a smooth finish or buffing away stains. It is a washable, cushioned file providing a better grip, allowing for more control and faster refinement. Cleaning Instructions: Put nail file under running water and brush the grit surfaces lightly. Do not leave immersed under water for more than 10 minutes. Pat dry and allow to air dry for 24 hours before re-use. Also available in singles.