I bought this to provide my cat with a safe space and not for closing him in. However, it is plenty big enough for a litter tray and small cat tree if that was the plan. It took a couple of hours to complete. No tools were required. It took some force to fully insert the panel corners into plastic clips and occasionally some bits would snap off. It didn't seem to matter as when it was all put together and the zip ties were added it was very robust. I was able to modify its shape and inner arrangement to suit my space also. It comes with a lot of spare clips and ties also.