Stepper motor direction indicator/control

Doesn't come in contact with anything hot, so you can print it with PLA if you want.

Press-fit on the extruder stepper motor.  Looks nice.  Useful in determining if your extruder is skipping or stuck visually.  Additionally, you can use the dial to manually extrude or retract filament (assuming your hot end is warm enough…)

I printed mine in yellow inland PLA, and it has been working fine for years.