Bark Box Principle: When the outdoor bark control device is within range of the barking dog, the microphone picks up the sound and the bark control device automatically starts and emits ultrasonic waves. The ultrasound is only heard by the dog, and the dog will stop barking because it associates its bark with this unpleasant sound. Suitable for dogs: the ultrasonic bark control device is a safe and effective method of dog training. When a dog barks, they intervene by emitting ultrasonic waves to calm the dog without disturbing humans or other animals. Anti-bark devices are suitable for dogs and can help you deal with annoying barking problems. IPX4 Waterproof: The shell of this anti-bark is made of IPX4 material, which is durable and waterproof and can be used in different weathers, such as rainy, sunny, cloudy and snowy days. Professional waterproof design allows you to use the dog anti-bark device without worrying about weather factors, bringing great convenience to your use. 3 Modes & 50ft Range: You have the choice between 3 adjustable modes, mode 1: within 15 feet; mode 2: within 30 feet; mode 3: within 50 feet; Testing device: Test whether the dog's bark box can be normal. work. Sonic Bark Stoppers are suitable for dogs of all breeds and sizes, allowing you to easily solve your dog's barking problem. Lightweight and Portable: The dog bark control device is small and lightweight, making it easy to carry. You can mount it on a tree, on a kennel or garden fence or place it on a table, the anti-bark box can be placed anywhere and is a lightweight anti-bark device suitable for indoor and outdoor use .