... sorry was out of town in the camper!
Our trailer came with four Sterilite 32-Qt. storage boxes. These were in the middle and stack two high. On the outside there were two double height boxes that could only be removed from the inside of the trailer. In essence there are four bays for either one tall box or two of the 32 Qt boxes stacked.
I promptly broke one of the 32 Qt. boxes by stepping off of the truck bed on to it accidentally.
My wife says the 32 Qt. are not available but we replaced them with the following from Amazon, they are near identical to what came with the trailer.
Sterilite 16558010 Sterilite 28-Qt. Storage Box
Amazon.com - Sterilite 2194-2263 Sterilite 28 Quart Clear Storage Box 1 - Lidded Home Storage Bins
We ditched the big boxes in favor of the 32/28 Qt. So we have:
Bay 1: no box. Have shore power cable, city water hoses, leveling blocks.
Bay 2 - 4: 2x 32/28 Qt boxes per bay.
Hope this helps!