I would consider buying brushes/filters from iRobot (or maybe another manufacturer). They "match" the Roomba but don't seem to clean well. The brushes/bristles themselves appear to be slightly thinner and shorter than the original Roomba brushes.
Dyson V8 Absolute: The Ultimate Cordless Vacuum for Effortless Cleaning
142 Review
iRobot Roomba 692: Smart Robot Vacuum with Wi-Fi, ๐ค Alexa Compatibility, and Pet-Friendly Features for Effortless Cleaning on Any Surface
138 Review
Vacuum cleaner Deerma DX118C RU, white/grey
144 Review
Xiaomi Mi Robot Vacuum-Mop Essential Robot Vacuum Cleaner, white
284 Review