I just purchased my second one of these little jewels and thought I should make sure everyone knows how great they are! I have had my first one at least five years and it was still fine...until I dropped it on my ceramic tile floor and broke it.
Otherwise I would not have needed a new one still. This type of file is so much more gentle than an emery board. It leaves the edges very smooth and I find they don't split or crack as easily. When the file gets dusty I just wash it off and it's good to go.
There have been some improvements made since I bought my first one -- there is a case, for one thing -- and both sides of the file are meant to be used. My old one was smooth on one surface, which seemed a bit silly. Of course, the price went up a little, to $10, but the case is nice and I got 20% off besides. They also have mini, travel-sized ones for $8. Both sizes come in pink or purple with the coordinated case.
I decided I did not need a mini, as I already have a D-I-Y version. That can go in my makeup bag.
I especially recommend this for you who have soft, peeling nails, that crack easily. This file will give them a smooth finish to your manicure without damage. One reviewer even stated it could double as a weapon! Now there's multi-tasking for you!