15cm diametered space provides enough large capacity.for your beautiful hamsterrunning, no need to worry that this ball toy will squeeze your pet. From exercise to running subject, making it more enjoyable for the hamster more motivated to keep in good shape.Fun exercise toy to maintain alertness and agility, also helps with physical activity.release their negative emotions. Designed with multiple air circulation bands, this exercise ball has high air permeability.àair, not suffocateyour hamster. Big for hamster yet small for you, its portable size is convenient for you to carry around.outdoors, allows you to use it whenever you want to gift to your loved ones.your little pet an exercise. Made of high quality plastic material, this ball is durable and sturdy, even if the exercise ball collides, it will not break, not easy to break.wear and tearcorrosion.