The nail file with grain thickness 100/180 and size 178 x 19 x 3 mm is suitable for straightening and shortening artificial and natural nails. The sides of the file are of different thickness to achieve a finer or stronger grinding effect. A lower grit number means the file is coarser and shortens the nail faster when sanding. We supply nail files in the following grain thicknesses: 80, 100, 180, 220.