Silent wheel with a quiet design, 30cm in diameter, gentle on pets. - Product Name: Silent Wheel 30 - Features: Quiet design reduces stress on pets - Size: 30cm diameter Thank you for viewing. We also have a used item (opened and tested once) of this product, so please feel free to comment if you are interested. Suitable for small animals such as sugar gliders, degus, chinchillas, and hedgehogs.