The Halo Small Pet Carrier fits securely around our small pet exercise ball (the Roam), allowing users to carry their small pets (hamster, gerbil, mouse, etc) in the exercise ball. It also provides a way for the pet to exercise in the ball while remaining stationary. Whether on the go or around the house, the Halo serves as an easy way to interact with your pet that is fun for both pet and owner. Never before has there been a safe way to walk your hamster. Our motto is: "give your small pet the life they deserve!"