This enclosed is very solid .....went together fairly fast with 2 people ...... instructions were a little unclear at one point but only took a small amount of time to realize what needed to be done otherwise they are clear to understand.....like the opening and the fact it is enclosed no large hole on the side but is still vented ......came with a small litter box however a normal size litter box will fit as well .....not a large one just a regular one from say a big box store.....great piece of furniture