The iFetch Too is an interactive, automatic ball launcher that provides fun for medium and large dogs and owners together. Features: Perfect for indoor or outdoor use. Launches the ball 10, 25, or 40 feet. It's easy to switch between those three distances or select the variable setting to keep your pup guessing. The iFetch Too "Tuff" balls are 2.5 inches in diameter. They are felted like tennis balls, but made for dogs and are non-abrasive on their teeth. Standard tennis balls work great, and any ball about that size should work. The iFetch Too comes with a built-in, rechargeable battery for portability. When you purchase the iFetch Too, it comes with three balls and an AC charger for 110 and 220 volts.