This is a silent running wheel for small animals, with a diameter of 30cm, providing peace of mind. - Product Name: Silent Wheel 31 - Target Animals: Small animals (hedgehogs, chinchillas, prairie dogs, etc.) - Size: 30cm diameter Thank you for viewing. I accidentally bought this when I first started keeping degus, and it has been stored ever since. Therefore, it is new and unused. The box itself has some scratches. To prevent the same mistake I made, please check the size before considering a purchase! (crying) ☆ Please note that it will be folded compactly for shipping. ☆ The product images displayed may appear different in color from the actual product. If you have any questions about the color, or if you would like additional product images, please feel free to ask.