This file does a good job and I'm pleased with it.
This makes an affordable alternative to a luthier's precision-ground fret-levelling beam, even if it is expensive compared to a regular file.
If you don't know what fret levelling is about, there are many tutorials online.
It's neither particularly long nor wide as tools for the job go, so you'll have to proceed carefully and check your progress as you go. Which you were surely going to do anyway, right?
It has a nice little bit of heft or weight to it, so that it can operate under its own weight - thereby contributing to even results.
It operates quite efficiently, so that the job will be done in just a few strokes.
In short, it's not the best tool out there that money can buy for the job, and it's not a cheap file, but for what it is, I'm very pleased with it.