This cat playpen is perfect for my Chinchillas.  Would have giving it a 5, but it was a bit hard to put together maybe took about 30mins and I need extra hands.  One it was togther it was easy to move around the room (on carpet).  The size gives my Chinchillas tons of room to run around have loads of toys and activitys to do and have space to relax and sleep.  I was worried the bars would be to far apart and they would get out but they haven't gotten out and have been living in it for about a month.  The shelves it comes with can be difficult to get in and out but once in they stay.  I also like tha there are four doors, a top section of door and bottom, and you can open one door at a time. It is heavy but that is expected.  Great playpen for my two Chinchillas!