Features: Quality steel bearing mechanism design brings them noiseless running wheel. Hamster exercise wheel encourages them to practice & keep the body healthy, enriches their activity & let them enjoys running happy. The running track is continuous without cracks or tripping problem. The running disc of the hamster wheel is made with plastic material, its easy to clean than wood materials. Its wonderful gift choice for your hamster or your family member/friend' pet. Specifications: Material: Plastic Size: Approx. 12cm: 12x12x6.5cm/ 4.72x4.72x2.55in 17.5cm: 18.8x18.5x7cm/ 7.28x7.28x2.75in 21cm: 23x23x9cm/ 9.05x9.05x3.54in Color: Blue, Pink Package Includes: 1pc Hamster Running Disc note: 1: Please allow 1-2cms errors due to manual measurement, make sure that you do not mind before you order. 2: Due to the difference between different monitors, the picture may not reflect the actual color of the item.