- Safe for Pets: Solid running surface, safe for your pet’s tail and feet. 2. Material: plastic disc + steel bearing, durable and safe. 3. Dimensions: 18 x 18 x 11cm. Suitable for hamsters, rats and other small animals. 4. Function: Provide your pet with more to explore and climb. Cute little exercise wheel to train your toes and nails. 5. Benefits: keeping the hamster healthy and active. The exercise wheel can greatly arouse your pets’ interest in exercise and keep them healthy.