[ContainerTed]

Yes, Sue. At the bottom of page 51 in that pdf document is the "TR1801" that fits my dimension description exactly.

And, yes, it is not a breakaway type. It's solid. It still needs some extra support from a carrying frame to move them around a lot (in and out of the garage during hardening off) especially when full of damp growing medium.

Thanks a bunch.

Edited to comment: I went back to Green House Megastore and found a similar product under Landscape trays. Seems like the costs are about $1.30 or so each in quantities of 50. I've also found some other similar products at the website noted by Sue.