I have a 7 month old Holland Lop, and she barely fits in this. Well, she wouldn't even go in it, so I had to actually put it on top of her to see if it would fit. She could hardly turn around in it, but she did manage to get out through the circular hole. I'm going to return this item after I build my own house for her. I spent like, $18 on this, and if you have a rabbit, even a dwarf, don't buy this item. Build your rabbit its own house with the $18+ dollars you would spend on this item.
However, the reason why I gave this 2 stars instead of 1 is because it would be great for any other small pet, like a guinea pig or maybe a ferret.