If you click on the link, it tells you the dimensions:
Dimensions:
* Total height: approx. 36.5 cm
* Side length: approx. 48.5 cm
* Length of platform: approx. 30 cm per side
* Length of ramp: approx. 25 cm
* Diameter of lower den holes: approx. 11 cm
* Height of lower level: approx. 18 cm
* Height of upper level: approx. 17.5 cm
* Side length of house: approx. 21 cm
* House door openings: approx. W 7 cm x H 13
* Window in house: diameter approx. 6 cm
To give you a rough idea though, I have a 3 by 3 CnC Cage, and its that big:
Or here in my old 2 by 5 CnC Cage: