Trust me, they're blooming enormous! And a devil of a job to get back inside the box...if you can get it inside the box. Ours hangs out as though its about to spring out at any moment.
Oh and they're not waterproof so if its going on the carpet you'll need to either line it with waterproof material or put something underneath.
Oh, and if you put a dwarf hamster in it......be aware they can climb the net sides!!!
On the plus side the piggies really like it!