I have 2 adult cats and a newly adopted 6mo kitten. The playpen was purchased for the kitten because she was having digestive issues so I couldn't let her roam freely. Now that she is better all 3 of them go in and out of the playpen all day long. I have a fullsize hooded litter box that fits perfectly thru both bottom doors. I do agree with other reviews about making the walls sturdier by adding zip ties or other secure measures. I also put zip ties on the corners of the 'roof' and will add to the shelves as well. I am happy I chose this product. The box was delivered w one side open a bit but everything was still wrapped and undisturbed.