Help your small pet to keep healthy! This exercise wheel is exactly the right thing you need. Run whenever it wants! This big and thick wheel is safe, quite and durable. Features: Exercise wheel for small pet such as hamster, gerbil and rat, maximum diameter 21cm. Adopt strong steel shaft and premium grade PP material; With thick wall and round edge. No gaping place, your pet won’t get its feet hurt or wrenched. Non-slip convex lines enlarge friction and enhance stability to avoid false step. Silent structure, your animal can run at night without disturbing others. Wide suitability, can be mount on various pet cage. A funny toy help to keep your pet slim and healthy. Specifications: Color: Pink / Blue (Optional) Material: PP Maximum Diameter: 21cm / 8.3"" Minimum Diameter: 19.6cm / 7.7"" Height: 8cm / 3.1"" Item Weight: 231g / 8.1oz Package Size: 22 * 21.9 * 9.8cm / 8.7 * 8.6 * 3.9"" Package Weight: 330g Package List: 1 * Wheel 1 * Screw Note: There might be footfall and slight wobble