Rubbermaid models 2218 and 2221
The 2218 is a 6qt for Hatch-lings
The 2221 is a 28qt for anything outgrowing the 2218, You typically would keep females in this until they are about 1500-1800 grams and then move them up to a bit bigger of a tub like 41 qt. You could keep adult females in the 28 qt tubs, but it doesn't give them that much room to be themselves. I'd personally choose to lose a few tubs in the rack for a ball python that will get to stretch out a bit more in a bigger tub.
Im not sure which model Rubbermaid has that's close to 40qt.
Hope this helps, or at least gives you an idea.