The Franklin Pet Supply-Ready Set Fetch Automatic Tennis ball launcher is the ultimate interactive pet toy. Your dog will love the distance this unit will launch the ball. They will keep coming back again and again. Once your dog places the standard sized tennis ball into the top of the feeder, the internal mechanism will process the ball through its chamber and an optional warning sound will be heard prior to launch for safety. The set includes a power adapter and official RSF tennis ball. Take this toy anywhere with its built-in carry handle and battery compartment. Batteries sold separately