Tubing bulkhead for connecting two different size PTFE tubes through a wall. FlashForge uses a 6MM OD PTFE tube while Amazon had 4MM OD PTFE tube. I had to make something to adapt the two and go through a plastic tote side wall. This is what I came up with.
5MM female, threaded end and 6 MM smooth end.
5MM Push-To-Connect (PTC) fitting: https://amzn.to/2WPgE9i PTFE Hose for the PTC fitting: https://amzn.to/2KUXrk6