Good buy, great price! Good for cats 15lbs and under. My cats are 15 lbs, 7 lbs. Cats well over 15 lbs with girth around the body will have a tighter fit. Length measurements are 17 inches diagonally (like measuring a laptop screen, Smart TV screen, etc.). Easy assembly. Comes in 2 parts - top tier, bottom 2 tiers with platform. Top tier sets into neck of bottom tier. Then you only have to turn top tier in a circular motion until it tightens. 4 stars given because cat jumped from top tier and cat tree fell over. Will look for something to permanently hold cat tree down. Otherwise, still a good buy for my cats.