My eggs are in a 15 qt sterilite tub with press and seal over the top, then the lid is also on.

Later this season when I (hopefully) have more than one clutch in the incubator, I'll be using some custom egg boxes I built out of panes of glass and aquarium silicone. I wanted to have decent sized boxes but also be able to fit as many in the incubator as I can, which would be six 12" x 12" x 10" boxes. I was initially going to use plexiglass but the guy supplying the glass had other ideas. From what I understand, the smaller the egg box, the less medium you can use, which makes it harder to keep the humidity up.