Is there a minimum size for dwarf hamsters in a transport box?

I have a little question, I'm going to adopt a hamster soon and wanted to ask if there's a minimum size for the transport box,

Here is mine, I once put it next to a PS4 controller so you can assess the size, and I myself find that it's enough for a not too long drive, right?

That's enough

Yes is enough. It's not forever.

That is easily enough for a dwarf hamster. Make sure you hold the box tight so that the hamster is not shaken so much and if possible put it in the future cage so that it can get out of the box independently.
Then he can decide for himself when he feels ready to explore his new home.

It should be around 20x25cm so that enough litter and a safe hiding place can enter. Because the smaller, the more stressful, as the hamster then naturally feels trapped.

I don't know exactly how big such a controller is, but it seems a bit small to me… If there's space for a hiding place and 5-10cm litter, it should be enough for a trip that is not too long.