Suitable for all dogs This anti bark device is specifically engineered for canines, considering the hearing frequency range common to all dogs. It uses advanced ultrasonic technology with three carefully designed ultrasonic frequencies tailored for dogs. The frequencies rotate across the three bands, preventing dogs from getting used to a single frequency and maintaining longterm effectiveness. Automatic anti bark device The device automatically detects barking and emits ultrasonic waves to silence it. It can help with your own dog, a neighbor's dog, or a stray. It features a 33foot bark detection range and 50foot ultrasonic coverage. Operating across three ultrasonic bands—1530KHZ, 20KHZ, and 30KHZ—it ensures effectiveness in various environments. Universally applicable indoors and outdoors Tested to be highly effective within a 33foot range, this anti bark device is suitable for both indoor and outdoor use. Its durable ABS casing resists corrosion, dust, and water, so it can be installed outside without worry. Whether calming stray dogs or stopping your neighbor's pet from barking, it works reliably—even in rain, snow, or other harsh weather conditions. Harmless and safe for humans This anti bark device aims to create a peaceful living environment without harming dogs. It silences dogs without any unpleasant side effects. There is no noxious smell, no electric shock, and no beeping noise. The device only emits ultrasonic waves in response to a dog's barking. These waves are customized to the dogs' auditory range, so humans cannot hear them and they have zero negative impacts on us.