Glass Nail Files are absolutely fantastic. They are much better for your nails than typical emery boards or files, as they are gentler and not as rough, and you can file with a lot less effort (and less back-and-forth over the nail means less damage.)
Glass files also last for years if you take care of them properly. Always return them to their protective sleeve after use, and after every few uses, when they are dirty with the white powder from your nails, give them a wash in warm water. This will keep them in tip-top condition and one file should last you a long time.
The files come in assorted colours.
