The best foot file

I have suffered from cracked heals for years, always made worse in the summer through wearing sandals barefoot. In a bid to keep the hard skin which is what exacerbates the problem at bay, I've tried dozens of different foot files, pumice stones and similar alternatives. The problem with most was that whilst they worked initially, very quickly they 'wear down' themselves and so become less effective. The exception to this, and the file I've now used for the past two years is the Tweezerman one shown. It has retained it's rough surface despite intensive use, and still does a fabulous job at smoothing my feet now! Combine the use of this with Scholl's daily moisturising cream for feet, and your feet should be up to open display for the summer :-)