I'm sorry but...
I hate to post this because their customer service is fantastic but the file coating wore off the first time I used these.  I emailed customer service and they sent me a replacement pack free right away.  Unfortunately, it's doing the same thing.  I don't know what I could be doing wrong since I only use them on natural nails.  Maybe because I get frustrated filing all one direction (slloooowww) and I usually file back and forth, which seems to create too much friction for these and the rough coating just comes right off.  So for me I'm treating them like disposable files.  Definitely not the forever files I thought I was getting.
Rating: 2 stars