For heavy duty nail grinding...
Wow, these are some hardcore emory boards!  I wish there was something in the package that says what the grit combo is for each color in the set.  But they can do some serious grinding.  I guess what I'm saying is that these are probably intended for professionals and even if I give six of them away, what's left is a lifetime supply for my personal use.  So all in all, a good deal.
Rating: 4 stars