• 1.0U: 18x18mm
• 1.5U: 28x18mm
• 2.0U: 38x18mm
• LED insert

I tested these using PLA, 0.4mm nozzle, 100% infill, and 0.2mm layer height on the Prusa Mini. These turned out great for my System76 Launch Heavy, which does not have proper keycap sets made for it. The LED insert, printed in clear PLA, takes some force to insert into the keycaps, but a small hammer will do.