Love this "playpen". Bought it to contain a mom cat and her five kittens until they can be adopted. I am using it indoors. It folds flat and even has a handy carry case. My ONLY negative is a big one...the bottom is only attached by a few pieces of velcro. I'm not sure why it wouldn't zip on the same way the top does? I'd be afraid to let me cats stay outside in this playpen due to this design flaw, as they could probably find their way out. I will most likely be adding snaps or something else along the entire bottom to make it more secure.