Beyond a joke, this thing has now power at all. As soon as it gets a bit of residences it will stop spinning.
If there was any way of giving it more power it might actual have a chance to do something.
Do not expect this to remove skin, it will sand a little but you'll get much better results with a hand sander. Also on mine when I put the battery cover on it pushes the batteries out of contact and so there's no power.