So, so [SEP] The power is a weaker than I expected. It does do the job, but I have to run the tool over a particular area a lot longer than I would have hoped before the dead skin is removed. My feet are not what I consider very dry, thus I don't have much to be removed! However, it works and this product is not expensive.  The replacement cartridges could become expensive if I have to replace them often. I don't know yet. I have only had the product a few weeks (purchased Feb 2015).  I will try to remember to update with that information when I have had the tool longer.