We bought this pen to be used for our new small breed puppies as their "den" during the night. It's tall enough for puppies and wide enough for them to be comfortable in but not overwhelm them with too much space.Putting it together couldn't be easier. Just slide the plastic pins it comes with on each corner and you're done. It's only 4 panels with one panel having the door.I'm sure it can be used outdoors as it's lightweight and easy to take apart and move around. For our purposes, which is indoors, it's the perfect size. Any bigger and it would just stand out too much in the house. We have a bigger pen for the basement as that's where the pups stay when we're not home. Overall, great little pen for the price and as long as your dog is not a climber or really good jumper, you should be fine with the height of the pen.