At some point I knew that we needed to replace the roller and side brush on the vacuum cleaner and that day came about 9 months of use! I always empty the bin after every cleaning, and even change the dirt filters (I wash one of these and let it air dry, although they're not meant to be reused). The roller was another problem. When he decided to eat the dryer sheet the bristles looked like they were having a better day so I decided to swap out the roller. We had a hard time figuring out how to open the door to get to the cutscene, but it turned out to be easy once we finally figured out how to open the door. The side brush is easy to replace as it slides up and down easily. Small brushes are good for removing clumps of dust that have accumulated in the bristles. It was a great kit that was always on hand whenever we needed to swap out parts.