This is tall, not very sturdy, the material used around is felt and burlap covering scratch posts.  I have two kittens, both ranging from 3-4 lbs and they are okay with this so far.  They have not climbed all the way to the top by themselves...I'm not sure if it's because they're still small and scared to or because this is on the wobbly side.  I put it up against a call but you can't really support it enough to eliminate all wobbling.  It also took a while for my kittens to figure out how to jump up to the top because the steps in here are not very "intuitive."