40" Large Cat Exercise Wheel for Indoor Cats - Durable Cat Running Wheel with Carpeted Runway, Fitness & Weight Loss Treadmill for Healthy Kitty Lifestyle (Black) - Perfect for Small Apartments & Active Cats

It took me more than three hours to assemble, but I'm a senior female and in no hurry. I did not use a power driver because I'm not skilled with it and it's heavy for me. I found that the little screwdriver that came with the kit was quite okay for the task, but of course much slower. I used a ratcheting screwdriver for the last few turns. Use the gloves that come with the kit or you will get a blister (Yes, I have evidence of this.). There are 115 screws to install (Plenty of extras were provided). It was a little challenging, but for me it's like a puzzle, especially when the instructions are less than wonderful and printed teeny. My husband offered to help but I shooed him away. I had a little uncertainty about which screws went where, but the information is there if you're willing to dig it out of the fine print and divergent English. Also, it's all logically designed and properly engineered to line up. The parts list omits the nuts that were provided for the underside of the long screws, but there wasn't any other place to put them, and they're pictured, sort of, with the rather cryptic wording. Basically, you use them with the wide part down against the wood. They provided a little wrench to hold them. If you overtighten anything both the plastic anchors for the wood screws as well as the metal seats for the machine screws will start to turn and they might not hold as well if that happens. This is another reason not to use a power tool. My efforts were rewarded when one of our three cats took to it immediately. The kittens are about six months old, and the little calico, who is usually bold and adventurous, was reluctant to stay in it when it started to turn, but she watched the orange boy with interest and will probably come around later. I enticed them into it with a laser pointer. The boy kitty kept using the wheel after I put the pointer away. Our third cat is elderly and off snoozing somewhere. She hasn't seen the wheel yet. I will update later if there are new developments, but so far this has been worth the price and effort. This thing is surprisingly sturdy and quiet. I'm quite pleased with it overall. The only challenge I foresee is keeping the young grandchildren away from it. I plan to hide it when they visit. I wouldn't expect the wheels to support the weight of a child, but under normal use, I think it will be fine. Editing a few days later to say that the reluctant kitty is now the main user of the wheel. Editing months later to mention that our big boy is back to using it. For several months none of them used it, and I was thinking of giving up, but as my daughter said, "He looked in the mirror and was like, I gotta do something about this." I would encourage people to use a laser pointer or a toy on a string to encourage cats to use the wheel. They like it when they associate it with fun. Catnip sprinkled on it is also helpful. BTW, the inner dimension of this wheel is about 39" /99 cm.. The title reflects the overall height, which is meaningless in terms of function. Our tom is a large cat now, and he's okay with it. The other two cats don't use it at all, but the young female will sit and watch her buddy use it. Possibly they each believe they are entitled to their own private wheel, but that's not happening. ?