The injection molded plastic push button on the top of my SodaStream broke in half.  I made this simple replacement (V2) as a temporary fix until I could buy a replacement button.  I printed it with Translucent Blue PETG so it would be durable.  I added a small threaded rod into the hole in the bottom to keep the return spring in place.  It's lasted more than two years so I no longer needed to buy a replacement. :)

Edit:

I decided it would be nice to have slightly more button travel so I created V4.  (No need for the threaded rod and has a snap on round button.)  I was a little unsure of using Natural PLA but with 4 perimeters it is very stong.  I've used it for several months with no signs of stress.