I use this mostly inside and it is fabulous. I have a small dog (Maltese), and this gives him lots of room to roam around.  I would not recommend for a large dog as jumping up onto the side, may tip it.  Easy locking together and at times I will not use 2-3 of the panels to create a smaller environment when needed.  Is water-proof so it is fine to use outdoors. Two friends who saw how easy this is to use (and put together), ordered one.