I modified Spartanvi's design to clean up geometry which was causing printing glitches for me. I've also included a blank and 8 key cap variants that I'm using for the game Star Citizen for various control buttons:

• Thumbs Up (Flight Ready)
• Power (Power On/Off)
• Rocket (Engines On/Off)
• Shield (Shields On/Off)
• Bullets (All Weapon Groups On/Off)
• Headlight/lamp (Lights On/Off)
• Key (External Doors Lock/Unlock)
• Exit (External Doors Open/Close)

Cap and stem are intended to be printed separately using clear filament for the stem and the filament of your choice for the cap(s). I attempted to include snap-together geometry for the cap/stem connection, but it's a bit hit and miss... I highly suggest using a little super glue to assemble.

I'm using the caps on an Xkeys 24 keypad, but I've also tested the fit on a Corsair Cherry MX Reds keyboard.