I actually bought three of these to act as waterproof containers for my bat detectors. I borrowed my advisor's costco card and walked up and down the aisles looking for a container that would be just the right size. Then I had to figure out how to give away three gallons of mustard. The last bit of it is sitting at school in the lab, waiting for hungry grad students to bring in their empty jars.
Then I made a rough drawing of what I wanted, took the parts in to the school workshop, and crossed my fingers. Tom did a great job of fabricating these casings.