Description: The pet running wheel is safer and more stable for pet to use for it is equipped with wide run track. And it makes no noise during running and it has adjustable height. Your pet will not get slipped because the lateral steps on the inner side of the wheel disc is slightly bumpy, which effectively increases the friction and prevents slippage during running. It is constructed of plastic material. There are two sizes for your choice: M and L. It is suitable for small pet like hamster, squirrel, pet mouse, etc. Item Name: Pet Exercise Wheel Material: Plastic Shape: Round Features: No Noise, Adjustable Height, Bumpy Track Size Details: M, Diameter: 18cm/7.09"(Approx.) L, Diameter: 23cm/9.06"(Approx.) Notes: Due to the light and screen setting difference, the items color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 x Pet Exercise Wheel