One thing you should know about before buying these, that they don't remove as much material as sandpaper with the same 'grid'. I think they're 2 to 3 times finer than sandpaper with the same grid. For eg. 800 is more like 1600 on normal sandpaper.

I use the 2000, 4000 and 8000 grit erasers to give the final shine on my fret jobs. Always get superb results with these.

My old guitar had been sitting in storage for 10 years and the frets were badly corroded.
These erasers cleaned up the frets with minimal effort and my bends are now silky smooth.
I definitely would recommend these for smoothing rough frets.

I have used ultra fine grit paper and other similar abraisives to polish frets but these are a lot easier to handle. I got the set so I could handle any surface condition starting with an appropriate grit down to the finest grit. Really shines up my frets and gives a smooth, glassy feel when playing. Bends are much nicer with polished frets!

I was disappointed with the shininess of just steel wooling frets during my setups. I looked on YouTube for how others were polishing frets. I saw Dremel tools. I've seen these fancy 3M polishing papers. But, what has really satisfied me is this method:

If the frets are in decent condition, but just a little scratchy/oxidized, I use steel wool to abrade off all the junk and provide a preliminary "cleaning polish." Then, I use the 4000 and 8000 grit-equivalent fret erasers in proper sequence to achieve a much shinier polish than what I was able to do with steel wool alone. It's very, very nice!

Here's another tip: Instead of like they show on the video doing 1 fret at a time with the fret eraser, lay that sucker long ways across 3-6 frets, and polish them in parallel. Dan Erlewine might cringe at me saying this, but my goal is to treat others' guitars as if they were my own, and this method yields a result that I am satisfied with! Try it for yourself and see!

I'll wager this is a better tool than was ever used on the magical guitars of the 20th century. It is for the most meticulous of techs and luthiers because it is not very aggressive.

Randy, from The House That Never Sleeps, had advised on the use of Fret Erasers from Stewmac. I had been using multiple files and sandpaper grades for years. After purchasing your product and trying, immediately the time and task was faster with better results. Thank you, team!

easy to use great for a quick tune

Excellent