HAPPY FITNESS ✔: The 6.9 inch (about 17.5 cm) hamster wheel provides your little hamsters endless happy runs, hamsters love the quietly spinning wheel, helping them enrich their night while maintaining their strength to continue exercising. HIDDEN SILENT BEARING ✔: Innovative ball bearing, silent rotation. Ensure the silent hamster spinning wheel glides smoothly and quietly. The hamster wheels are quiet, no annoying squeaks or rubbing or noise from the center axis. Even when hamsters are on the track, the track and hamster wheels rotate for quiet nights. DUAL USE OF STAND AND CAGE ✔: Hamster wheel with stand, freestanding or attached directly to any metal cage, the large hamster wheel is easy to install. Hamster Running Wheel The reasonably sized running drum and wide running track provide a relaxed back feeling, no need to bend over while running, allowing your pets to enjoy endless running time. SAFE - STRONG & DURABLE ✔: The gerbil wheel is made of high quality material, chewable, beautiful and delicate. Sturdy rat wheel design for reliable standing and support while running or walking. Hamster wheels are best suited for hamsters, gerbils, hedgehogs or other small animals. EASY TO CLEAN: The Hedgehog wheel features a fully open design for easy deep cleaning.