Nail file N4Y A good all-round file. Grit 100/180 Can be used for all kinds of file work. The file is used both for gel nails and acrylic nails. This nail file can be used to file off gel nails, but is also good for filing the length of nail tips. It may be used for the length of your natural nails. After you have applied your gel or acrylic, you can use this nail file to correct any unevenness in the nail so that it has a completely smooth surface. Grit in a nail file means coarseness, the coarsest nail file is usually called 80 and the finest 240. Let the nail file do the work, if you press too hard with the nail file, you will wear it faster.