: Made with pet safe materials.Relieves boredom and increases activity level and giving him a fun spot to playIdeal for hamster、 mouse and other small furry animals.Encourage healthy exercise in a secure and safe wayMakes a great temporary holding area to keep your furry friend while you clean their home4.7-inch diameter .For dwarf hamsters、 mice、 or other small animalsFun exercise toy to maintain your pet's alertness and agility.Provides interactive fun for the pet and the pet owner