"This pen is not very stable for indoor use. It has no door, and the two ends connect with 4 hooks similar to what is on the end of a dog leash. One good jump and the pen is on it's side. I do not feel safe leaving my 35 pound puppy in it. I got it because it was tall enough to keep him in, but it is not very stable when used indoors without the ground stakes. The only way to close it up is by using the 4 separate clips they give you - therefore it also takes too long to open it up to get him out."