Mont Bleu Set of 3 Rainbow Crystal Nail Files Quality matters. So that's what you'll find in every element of these stunning crystal nail files that preserve quality where it matters most in your nails. The glossy Czech glass is tempered for extra durability and the crystal nail file comes with a lifetime guarantee and effective coarse filing surface for extra-precision shaping. Built to last, tempered twice There is a tempering method that has revolutionized the industry, and it has evolved from the Czech techniques which transformed the production of crystal nail files. We utilize these ground breaking practices to ensure our files do not degrade in quality over the years, standing up to frequent use. Crafted from hardened Czech glass alloy, this nail file is renowned for its durability. Our double tempering process multiplies the effect, making them even stronger and allowing you to look after your nails with ease for generations. Practical yet luxurious Hygiene matters as much as durability, and for this reason each of our files comes in a protective black pouch. With files in 3 sizes (3.54, 5.31 & 7.68 inches long / 90, 135, & 195 mm long), you'll always have a size to suit. So, whether you're dressed to impress on a girls' night out, working in the office or at home having a relaxing manicure, this really is the only nail file set you'll ever need!