I bought this to replace another cat tree that had shelves that would dip every time my extra large kitty would jump on it.  I was afraid that it was going to send my cat crashing to the ground.  This cat tree is much more sturdy and supports a 25lb cat quite well.  The front support on the lower shelf is purrfect for those bigger kitties and the top shelf is generously sized so that they can lounge about without hanging over or falling off.  The base makes a purrfect hiding spot for the smaller cats and easily fits one under 20 lbs.