❀The Hamster Exercise Wheels are made of high quality plastic materials; respectful of the environment in order to protect health; pets. This product uses new PC material with a lock. It is easy, convenient and quick to set up this product! ❀Hollow design on both sides of the racing wheel makes the racing wheel more breathable and allows hamsters to perform exercise. aerobics. There are several safe and breathable ventilation holes on the ball, and your little pet can play in it for a long time! ❀12cm in diameter. Suitable for dwarf hamsters, mice or & agrave; other small animals. Please check the size before ordering. Recommended & oacute; for dwarf hamsters. ❀ Fun sports toys that can keep animals nimble and agile. Provide interactive entertainment for pets and pet owners A great playing ball for hamsters. You can place your pet & agrave; inside while you clean his cage.