Unique Design Ultrasonic Bark Stopper A safe, humane deterrent that uses ultrasonic waves. It is not harmful to dogs or people and provides a gentle but effective signal to encourage quiet. Designed for dogs, its appearance resembles an alarm clock. 4 Modes of Ultrasonic Adjustment Bark Box offers four modes to adjust the frequency: T-test mode, 1 low range up to 15 feet, 2 medium range up to 30 feet, 3 high range up to 50 feet. When the dog barks, the red light flashes to show the ultrasonic is active; the green light flashes after the barking stops to indicate wakefulness. A red light also flashes when the battery is low. IPX4 Waterproof Safe Anti Barking Device Housed in an IPX4 waterproof enclosure, it withstands bad weather and continues to function outdoors. Its robust, lightweight design makes it suitable for outdoor use, while still being compact enough to carry. Applicable Range and Placement Effective for controlling excessive barking in apartments, condominiums, or homes with nearby neighbors. It can be mounted on walls, fences, or trees, indoors or outdoors. Its sound waves reach up to 50 feet, helping deter neighbor dogs or stray dogs from excessive barking. Practical Use Scenarios - In an apartment hallway or living area to reduce neighbor disturbance. - On a balcony or fence line in a condo to address nearby barking dogs. - In a yard or garden to deter stray or neighborhood dogs without confrontation.