Hey there...I bought one of these several years ago and use it off and on. It is a vibrator obviously and runs back and forth. It works well as you get used to it, however it can only go in a close area one way because it vibrates back and force and therefor will contact the sides of a close space and not work. It IS very strong but sometimes you cannot use the entire surface of the medium (it has a very strong sticky backing as well) so sometimes seems wasteful to change the paper before it is all worn down on every side. I would purchase it again though, for the price shown here! It a lot cheaper than when I purchased !
Hope this makes some sense.
Jay