Feature: 1. Running ball can provide the amount of exercise it needs, which is very beneficial to the pet's muscle stretching and myocardial function, and can greatly extend its life. 2. The lid is designed with press button, with a snapping point in the middle, which will snap on when the concave and convex points correspond. It will not fall off during running, and only one side can be opened. 3. Air vent design, hamster will form a wind flow channel when running, running and breathing, staying inside will not suffocate. 4. The ball is easy to install and a good toy for the hamster entertain. 5. 2 colors available, easy to get what fit for your pet. Specification: Item type: Golden Hamsters Exercise Ball ToyMaterial: plasticDiameter: Approx. 18.5cm/7.3inWeight: Approx. 374g Purpose: hamster play, exercise . Package List: 2 x Running ball semicircle2 x Connection slice1 x Screwdriver6 x Screw