great nail files [SEP] these are very good nail files they work very well and lasts through multiple uses i have natural nails and i i find that the two different grits work well with smoothing edges and removing sharp corners of nails after trimming i was replacing my old files after every use and the sand was flaking off and getting all over my floors i did not have any problems with these doing that overall it is a very high quality product and i would highly recommend it especially for professional use