This is her 2nd wheel. Important: it took 2 weeks of training for her to learn to control, and not fear, the wheel. Also important: I knew she was a cat that loved to run. She ran around the house for no particular reason. Our other cat isn't active in that way. Okay, she's lazy...loves food and prefers to eat. The first wheel, which we put in the basement, is larger, made of plastic, and has a rubber surface. She loves it but I wanted one to fit in the bay window. Now she has two. She loves the carpet of this new one. It was easy enough to put together, took 2 of us 1.5 hours. The pieces fit together well. It comes with one screw driver. Your helper will need to bring a second screwdriver.