Very efficient!
I don't think I have ever had a foot file that did such a wonderful job of getting rid of all the dead and cracked skin on the bottoms of my feet. I've also used it on dry skin on my elbows.  Gets rid of calloused areas without damaging skin or causing cracks!  I LOVE this!!!  I have bought several for gifts and one of the gift recipients has in turn, bought them for gifts also.
Rating: 5 stars