Description: Material: Plastic Size: 12cm/4.72 inches Color: Blue/Pink (random color) Feature: 1. Safety anti-jamming design: The face of the rollers is smooth and the edges are widened to prevent hamsters' feet from getting stuck or injured. 2. Silent operation: The bearing structure design ensures smooth operation with low noise and does not affect night rest. 3. Easy-to-clean structure: Convenient for cleaning, maintaining hygiene and preventing bacterial growth. 4. Strong durability material: Made of high-quality materials, it is resistant to biting and abrasion, making it suitable for long-term use by hamsters. 5. Promote exercise: Help hamsters exercise daily, enhance physical fitness, relieve stress and improve mood. Attention: 1.Due to manual measurement, there may be a 1-3mm error in product dimensions. 2.The color of the product may have errors due to objective reasons, and the actual product is the main focus. The product includes: 1* Hamster running ball running wheel