We got this for our outdoor cat to come inside during the summer heat. He has plenty of room to lay down and can switch positions. We can also fit a litter box in there.

Like many others, we put two shelves together to make a larger platform and that's where our cat spends most of his time. The two shelves together make it so we can't open on of the four doors, but that is no problem at all.

The parts don't fit together all that well, so we used plastic ties to strengthen the structure. It will just be a pain when we want to take the playpen down in the fall.