not very powerful [SEP] this foot filter is easy to hold and i really like that there are three different grained heads that rotate but stay attached you do not have to constantly change the heads on thishowever when you rotate the heads you have to hold down a button on one side and then use the very small rotater to change heads it makes it a bit difficult to change the headsalso i had problems with it constantly stopping while i was using it and my calluses are not even that bad if you just have a bit of dry skin this will probably work for you otherwise you are going to want to skip it