This ultrasonic training aid uses a high-frequency pitch that is only heard by dogs and cats. It helps reinforce your pet to follow your commands, such as sit or stay, as well as correct bad habits of barking or jumping. Used by many professional trainers to effectively train dogs or cats by maintaining their attention. Best if used from a distance of 6 feet away. Has a 20 foot range. Requires 9 volt battery, not included.