So even with this short-nail file. Unfortunately it is a bit too thick and difficult to coarse (the fine side). The file is probably something for the rough and the tip is not suitable particularly around the nails clean.
All in all rather disappointing and unfortunate that twin has not a little more invested in its operation.
Conclusion:
+ Design very classy and simple
+ Processing perfectly
+/- Grit could tend to be gross (depending on your preference)
- Total too thick and the tip is to use rather bad