Please purchase after enabling Eco-Mercari delivery, which is located at the bottom of the purchase screen. If you do not enable it, your purchase will be canceled. I bought this at a pet shop during a trip to Taiwan. I loved it because I couldn't find it in Japan, but I'm not planning to get a pet for a while, so I'm selling it. I'm also selling a Lion House. Bottom: 10cm x 10cm Side entrance: 5cm wide x 3cm high Roof window: 3cm wide x 3.5cm high My golden hamster used this. She weighed about 120g. If your hamster is a bit chubby, I'm worried it might not fit through the window, so I think it's suitable for golden hamsters that are small to average size.