I love these pens since you take them fully apart or use as many panels as you want.  They are so easy to clean - just take them to the driveway or patio and hose off.  Nothing sticks to them which is great for puppies.  Only drawback is if you have larger or heavier dogs as the panels are a little too flexible and tilt too easily if the dog puts it's front paws up on them.  They are great for puppies and my adult dogs who are good in an open pen.  Would not hold a hyper or determined dog or puppy though.