Description: Made of high quality wood material friendly and for your . Helps your hamster exercise more and develop agility. Widened and thickened wood base provides reliable and stable mount for the exercise wheel. It not only serves as exercise toy preferred for small pet sports activities but also a nice decoration. The wooden wheel is noiseless when with this wheel it will not disturb you. Specification: Material: Wood Size Chart: M: Outer diameter 21cm/8.27inch inner diameter 19.2cm/7. base width 12cm/4.72inch overall height 23.5cm/9.25inch wheel outer width 8cm/3.15inch inner width 7.2cm/2.83inch; L: Outer diameter 29cm/11.42inch inner diameter 28cm/11inch base width 14cm/5.5inch overall height 32cm/12. wheel outer width 9.5cm/3.74inch inner width 8.6cm/3.39inch; Package Includes: 2 Pieces Small Pets Exercise Wheel Note: Color might be slightly different due to the color calibration of each individual monitor. Please allow slightly measuring deviation due to manual measurement.