This pet pen was easy to assemble and seems to be of quality construction. It is easily taken apart but the panels can be secured together with the provided zip ties to make it a more permanent structure. Our dog, who is a 6 month old medium sized goldendoodle, fits in it just fine. Although I would not leave a dog her size in it for too long. This is a good size pen for dogs her size or smaller. A smaller dog would probably be able to use it more as a play area, whereas the pen is more like a large crate for a medium sized dog. I would not recommend this for a large dog.