Supposedly it's for larger cats.  It isn't.  My big fella is about 11 lbs. (or maybe 13, there are some questions on that because of the nature of the scale) but there is no way he's going to fit comfortably in the top shelf.  Which is a pity, because our five-month old kitten was fascinated with the entire tree and wouldn't stop playing with it the entire time we were putting it together.  He was in it when we were screwing it together!  The dog, who is only 9 lbs., was in and out the little house at the base, he loved it, too.  But that top shelf just won't fit my big fella, who is only 13 months old and still loves to play, play, play. I would NOT recommend it for cats who are larger unless they want to stay on the bottom.  They both loved the fish toy and the suspended balls.  Just wish it was big enough for my big guy.  Wasn't too hard to put together.