Assembly took realistically 2 to 3 hours using the hand screwdriver they supplied. High quality, well constructed. Rolls smoothly. They advertise it for big cat 17 pounds or more but my 14 pound cat has no trouble operating it. Only concern is the “Sharp“ edges… They do supply work gloves, and sandpaper to smooth the edges. I feel that this last ‘construction step’ should be done already for the consumer. Otherwise, very, very pleased with the product. Note: at first, my cat was skittish about it, but I trained him in six easy steps. Now he runs to it when he knows I’m going to unlock it and he has had his “Aha” moment. ie walking on it doesn’t just get him treats… It just feels good to walk on it!