A mesh puppy pen is ideal for travelling or taking your companion to places. It is easy to carry, and it can be folded for easy storage. There are also plastic models, but your pup might think about chewing through them, which is not desired. This way, they can get out and the entire purpose of the pen is ruined. What you place inside the pen matters, but the key is to make sure your companion doesn’t use it to relieve itself. Otherwise, they will associate the pen with going outside.