These are printer rotation visualizers, reminscent of the Porsche turbo twist wheels. One is for the extruder axis and the other is for the x-axis.
This is inspired by Extruder rotation vizualizer by mikolaszuza.
The extruder rotation visualizer uses two 8 x 3 mm magnets for mounting to the extruder motor axis. There's a notch for the magnets to fit in the part. No glue required.
I think the x-axis visualizer is actually a bit nicer since the x-axis is a lot more active and the visualizer spins more frequently. This one mounts on the shaft of the x-axis motor. No glue or magents required.