Can be used for holding or growing pen for smaller birds. The inside dimensions are 36" Long X 30" Wide X 9 3/4" High. There are sliding door panels on front and sides that have 1" X 4" mesh. the top half of the panels are open and the bottom half has an adjustable gate that is adjusted to allow the birds access to feed and water troughs hanging outside the cage. Similar to #PGB, except it has no heater.