My Roomba 600 is a bit dated. One day I noticed that getting new parts was becoming difficult. Now I have a box of parts. Filters, brushes and co. to keep my Roomba running. They were clearly used as there was very little dust on them. There is no wear and tear on them. I originally bought these because my Roomba made a clicking noise when moving. I finally found out that the noises were being made when there was a lot of hair wrapped around both ends of both brushes. After pulling out all 4 ends and removing all hair, the robot is much happier :)