snap-on attachment for a Rigid vacuum nozzle to allow it to roll on the floor instead of scraping the floor. This item can use standard 608 bearings but I print my own bearings using -
https://www.thingiverse.com/thing:2598427
If you print your own, use the model with 5 balls, it seems to work best for this application.
PLA, 4 perimeters, 20% infill, supports only from the build plate
The author hasn't provided the model origin yet.