hamster exercise ball 18cm Hamster Exercise Ball Transparent Accessory Gerbil Ball Wheel Toy PP Material Hollowed Out 7inch Hamster Multiple Vent Holes Small Animal Toy Blue.Diameter about 18cm/7inch great for hamster and other small animalsHamster exercise ball made of PP materials environmentally friendly transparent ball convenient for the owner observe the pet s every moveHamster running wheel with multiple vent holes on both more breathable and allows hamsters to aerobic exerciseThe both cover of the hamster is designed with buckle lock design screw fixation it can be molded with a light press convenient assembleFun exercise toy to maintain your hamster alertness and agility provides interactive fun for the pet and the owner18cm Hamster Exercise Ball Transparent Accessory. Gerbil Ball Wheel Toy PP Material Hollowed Out. 7inch Hamster Multiple Vent Holes. Small Animal Toy Interactive Gerbil Running Wheel. Pet Hamster Jogging Ball Toy Cage Accessories.