A pumice stone is a natural product made of volcanic lava and is a natural way to remove calluses from hands and feet. Please note that a pumice stone should not be used dry, but with a small amount of water.
I like the pumice stone ok, but it is a bit big and awkward to use around my toes. It is better for just the bottom of my feet. I also didn't realize chunks of the pumice stone would fall off when I scrub my feet. It was good to try, but I would try another one next time.