Review (1/5): I used it once so far. It worked well ...
I used it once so far. It worked well. It took two AA batteries. A little bit hard to pull the rubber wrap off.
Updates (6/12/2018): The device had been broken. The part that held the metal needle, which was connected to the brush holder was broken. It first broken partially. And then total shredded. From the sound that it made after it was broken when you shake the handle, it was made from plastic. I have only been used the device several times so far. Downgrade the ratings.