A replacement switch cover for the Casio PT-87, it's is a replication of the original design and implements the same compliant mechanism on the rear.
This fits many other Casio Keyboards and many other switches or slider potentiometers.
Material: PLA (I would imagine most materials will work, I used glow in the dark PLA, it was very brittle but still worked)
Layer Height: 0.2mm or less
Nozzle: 0.4mm but may print with 0.6mm
Supports: Yes, print flattest side down (upside down)
If you're having trouble with the mechanism try slow the print down.