Turn your MK3 into a Time Travel Machine with the Prusa MK3 Flux Capacitor, it can also be used as a rotation indicator for the extruder motor.
Print individual parts then super glue together, kind of a pain, but time travel isn't easy. Glue a 8mm (.315) diameter magnet on the back of the center part. Home depot has a 10 pack for like $4.00.
Printed at .2mm layer height, used PrusaControl to add the color change on the part with the lettering.
I take no responsibility to any issue caused to the Space Time Continuum :)
Video in action: https://youtu.be/fUgHyT4Zc_Y
I also Added new bezel Flux-02-R3 for use with the updated R3 extruder. I haven't upgraded yet so I haven't tested this yet, but used the updated MK3 Solidworks models for testing, to modify, so hopefully it fits OK. I have the MMU2 on order, so will upgrade my extruder when that arrives.