iRobot Roomba 500 Series Brush Gears (works with red or green CHM)<div style="text-align: left;"><strong>[Product Information]</strong><br><ul><li>6 Replacement Gears for roomba 500</li><li>Works with Red and Green CHMs</li><li>Not compatible with the gray CHM</li></ul></div><img src="http://ecx.images-amazon.com/images/I/41WsgJTV3mL.jpg" noproxy>