An arboreal dwarf species. Avicularia minatrix comes to mind.
As a temporary cage for a juvenile that would be fine until it got too big but it wouldn't work as a permanent cage. I wouldn't keep a tarantula any larger than a few inches in there.
Might be fine for a house spider,,fishing spider perhaps, too small for tarantulas, huntsman and such.
I kept mantis in such cages.
Maybe great for caterpillar.