My Roomba Pet of the 500 series no longer really wanted. I have the Brush completely renewed and lo and behold, he is as good as new. Everything is wiped away again, there are no animal hair longer around. The Brush should probably be renewed from time to time, especially if you, like me, a dog has. It had already wrapped wool of the children who go by brushes broken. A wear part precisely. I'm very satisfied, will replace the brushes more frequently.