"" Help your little animal stay healthy! This exercise wheel is just what you need. Run it when it wants! This big and big wheel is safe, stable and durable. features: Exercise wheel for small pets like hamsters, gerbils and rats, maximum diameter 21 cm. Adopt a steel shaft and high quality PP material; With thick wall and rounded edge. No gaping place, your pet won’t hurt his feet. The non-slip convex lines increase friction and improve stability to avoid false steps. Silent structure, your pet can run at night without disturbing others. Wide convenience, can be mounted on different animal cages. A fun toy that helps your pet stay slim and healthy. Characteristics: 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: 345g / 12.2oz Package list: 1 * wheel 1 * screw Note: There may be steps and slight swings when