[cypher]

The bar spacing might be a little big if you had really young babies for an adult or almost fully grown robo it would be ok except for the gaps at the corners & top, high cages can be dangerous for dwarf hamsters, I don't think robos tend to bar climb as much as the other dwarf species but they can & some will so there is a big risk of falls unless you set the cage up very carefully.
If you want a barred cage I think the Savic Mickey 2xl is the safest option, narrow bars & a good height.