I'm going to first be honest in saying I was VERY skeptical of a glass file having the ability to shine my nails, without damaging them. I am happy to say that I was pleasantly surprised when I first used one. No damage to my nails, and a perfect shine to them! I love that this file is dual purpose, and small enough to fit in my purse, or zippered wallet for quick on the go carrying.
It really works!