Pet playpens are ideal for puppy potting training, introducing a new puppy to a resident cat or dog and for keeping your pet safe and secure while traveling. Whether you have a new puppy or are seeking a containment solution for an older animal with incontinence issues, you will want a durable pet play pen that will securely contain your animal. We took a look at 4 of the top sellers testing them for security, durability and portability. We were surprised to find the number one seller was deserving of a big thumbs down on all three criteria. #1 - Heavy Duty Dog Play Pen 40" 8 Panel Review BUY IT NOW This heavy duty playpen is appropriate for both indoor and outdoor use. It is marketed under several brand names, with the Best Pet brand being the most widely recognized. Each of the eight panels is 40" tall and 31.5 inches wide creating just over a 21 square foot play area. The individual panels are lightweight, however the the complete product box weighs 55 pounds.