The side brushes are approximately 1/2 inch longer than the original brushes. When I installed them and tried to clean them, Deebot stopped and reported that the side brushes were tangled. Following another reviewer's suggestion, I cut 1/2 inch off the ends of the brushes and tried again, but Deebot stopped again and reported that the side brushes were tangled. The problem seems to be that the plastic holding the brushes is longer than the original brushes and protrudes about 1/2 inch past the robot's body, so they stop spinning when they hit the wall at the edge of the room . The second possible explanation for the problem is that the longer plastic holder makes the brushes stiffer, causing them to smack against the wheels and prevent them from turning. If I trim the brushes even further to prevent contact with the wheels, there aren't enough brushes to work properly. The included filters and main brush fit, but the side brushes simply do NOT work on the Deebot Ozmo 920. I had to reattach the old brushes so Deebot could clean.