The worst thing is the curved bottom cuts down the size considerably hard to get deep substrate and balance a big wheel and water dishes tubes and penthouse useless green shelf proving dangerous for a chubby fully grown dwarfie who squeezes into tiny gap to get to top ignores ladders tried 3 types. On the plus side its compact when space is short good ventilation from top being completely wired adapt with home made supported platforms hamster Pete seems very happy with it and can't understand why I'm so critical it meets his needs.