Suitable for Various Small Animals - The silent hamster wheel inner diameter is 8.7", the runway width is 3.35" and the height is 10.3". It's reand commended for Chinchilla, Syrian Hamsters, Large Gerbils, Dwarf Hamsters, Rats, Lemmings, Degus, etc. This hamster toys helps hamsters relieve boredom and stay active and healthy. (NOTE: Does Not Include Any Suction Cup!) New Premium Bearings - The hamster exercise wheel uses high-precision bearings to achieve ultra-quiet rotation. Ensures smooth, quiet, and durable operation of the running wheels. These advanced bearings reduce noise and improve wheel stability, providing endless running fun for your hamster while allowing you to enjoy a peaceful night.  Durable and Attractive - The hamster treadmill is made of safe, high-quality PC material, the hamster wheel is resistant to gnawing, sturdy, and drop-proof. Its sturdy structure provides quiet and reliable support when running or walking. Available in a variety of colors, it adds a touch of freshness to your pet's living environment. Promote Health and Well-being - The hamster wheel encourages regular exercise, helping your hamster maintain muscle strength and mental wellness. Its smooth surface and stable structure ensure a risk-free workout every time.  Thoughtful Construction for Pet Comfort - Prioritizing your pet’s safety, this wheel features no sharp edges or joints, making it a comfortable and enjoyable space for your hamster to play and exercise. Warming Note - Please strictly follow the instructions during installation. If the screws are not installed properly during the installation of the hamster cage, do not forcefully tighten them, which may cause the hamster wheel to get stuck and unable to function properly. 8.5 Inch Super Silent Hamster Wheel