The SquirrelStop automatic spinning squirrel deterrent safely and harmlessly protects your hanging bird feeder from hungry squirrels. When a squirrel climbs onto the feeder, the increased weight starts the SquirrelStop motor, which spins the feeder and causes the squirrel to jump off. Since birds weigh much less than squirrels, they don"t activate the SquirrelStop. Squirrels soon learn to leave your feeder alone - and birds can enjoy their food undisturbed. Setting up the SquirrelStop is easy. Simply hang the device where both the SquirrelStop and your feeder will be at least 40 cm (16 inches) from the nearest object. Fill the feeder with seed (ensuring the total weight of the feeder is less than 10lbs (4.5 kgs)), hang the feeder from the SquirrelStop, and turn the device on. That"s all there is to it. When it"s time to refill your feeder, switch off the SquirrelStop, remove the feeder, and fill it with seed. Then hang the full feeder from the SquirrelStop, and turn the SquirrelStop back on. The SquirrelStop automatic spinning squirrel deterrent is constructed of durable, high quality UV-resistant materials, and has been designed to provide many years of reliable service. Requires no assembly, and is easy to use . Operates on three D-cell batteries (not included).