Several lens caps
You can add your text to the front surface. The photos show my logo, but obviously the files don't have that.
Needs very little support
Needs no glue
Works well with lens hoods. center pull buttons.
Plastic printed spring. Depending on what material you print it out of will affect how long it will last the spring has very little movement, so it should last a long time.
I printed in PETG, but PLA should work fine.