great glass files [SEP] these files are fantastic i really like the fact that they are not etched like any other glass file they do a great job at filing natural nails without all that ear splitting teeth hurting grinding noise other glass files makeas far as buffing polishing goes yes they do make a naked natural nail shiny but unless your nail is free of bumps humps divots etc it is going to take a long time to shine the nail evenly what you end up doing is making thin weak spots in the nail which will cause breaks or cracks as the nail grows out because these files take off a lot of nail you can get shinier nails quicker with a base coat