Kaytee Run-About Balls provide the perfect outlet for your under-sized pets over-sized energy. These durable exercise and play balls let small animals roam free without getting hurt or lost while creating interactive fun for pets and owners alike. Great way for your small pet to exercise Keeps pets safe when out of the cage Ball glows in the dark Mini Run-About Ball Dimensions: 5 Wide Regular Run-About Ball Dimensions: 7 Wide Kaytee Run-About Balls provide pets and pet owners with interactive fun during playtime. They also make a great temporary area to keep your little critter during cage cleanings. Run-About Balls are ideal for a variety of small pets including dwarf hamsters mice hamsters gerbils and more. For added safety use your Run-About Ball on Super Pets Hamtrac Raceway and provide your pet with a controlled exercise environment.