This is a fidget spinner that can be printed in a single print with no bearings. It relies on a captive bushing that acts as the bearing. It tries to put as much mass as possible to the edge to increase spin time.
Definitely not as good as ones with bearing. On the other hand, costs about 50 cents in plastic for the large, and 15 cents for the small.
I sprayed some lubricant into the crevice around the hub and it made a big difference. Can get spin times of 6 seconds.
Would also suggest printing in nylon to make it extra smooth.
Also scad attached to allow you to customize.