Suitable for dogs of all breeds and sizes, it can effectively block the barking of your dog or your neighbor's house, prevent the dog from barking at a certain time, and the ultrasonic bark controller has an effective distance of 25 feet. Outdoor ultrasonic bark control device has 3 adjustable ultrasonic range levels and test mode: low range, medium range, high range, test mode (for verifying the function of microphone and speaker) The ultrasonic frequency is harmless to pets and is completely inaudible to the human ear. It provides a safe and effective training tool for your dog or neighbor's dog to stop barking. Valid for most dogs in the range. The anti-bark device is durable and waterproof. It can be hung on trees, walls or fences to prevent your own dog or neighbor's dog barking and can be used indoors and outdoors. The new dog barking controller uses a carefully designed mini shape that is easy to place and hide. The two-color indicator shows if the electricity is fully. When the outer bark control is within range of a barking dog, the microphone picks up the sound and the device is automatically activated. The outer anti-indent control emits an ultrasonic sound. (Ultrasound noisecan from dogs, but is mute to humans) Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.