Review (5/5): Must-have!!  A+++  Best set of files for someone to buy for self, work, and for the entire family to use.
The best files ever, hands-down. Had them for a solid 6 months, still going strong. I purchased another brand 5 pack here on Amazon and they suck; they all got weird and really rough yet didn't file anything, not even the rough edge of a plastic bottle I had cut to use for a craft project.
The Mont Bleu still have a great filing surface, don't have cheap-o glass feel to them (some I've gotten on Amazon state they're from Czech R. but are still crappy knock-offs) These files are really fantastic, they can file down length in no time, smooth out a tear or split on a nail, refine the delicate corner of a fingernail, & are just perfect for regular finger/toenail maintenance.
Glass really is best because it doesn't cause my nails to split. These Czech glass files are so well made! I even file my kids' nails with these, my 7yo has learned to do her own fingernails with one of these files too!The grit on these is perfect: I never experience micro-shreds (look it up, it's the main reason nails split or break at the free edge) that catch on things and enrage me to no end. Emery board and traditional nail files WILL wreck your nails!
Buy these, even if they break (and it will happen so get ready to buy a backup) you can still use the pieces because they're not sharp like a shattered drinking glass or a broken dish.
Good luck!