" Rainbow Run-about Balls have been a favorite pastime for years providing pets and pet owners with interactive fun during playtime. Sized perfectly for hamsters and gerbils these colorful Run-about Balls provide the perfect outlet for your pets excess energy. Available in four colors Rainbow Run-about balls are a cool temporary area to keep your furry friend while you are cleaning their cage. For added safety use your Run-about Ball on Super Pets Hamtrac Raceway and provide your pet with a controlled exercise environment."