1Easy To Use: The anti bark device is designed like an alarm clock, which can be hung on a tree, indoors or anywhere in the yard, and can be placed on a table or other places at will. 2Sensitive: Ultrasonic outdoor dog barking control, when excessive barking is detected, the microphone will sense the bark and activate the components, and a safe sound will be emitted. 3Safe: This barking controller is harmless to pets and human ears, but dogs are sensitive to these waves, it is an effective training tool for your dog or neighbor dogs to disturb. 4Long Distance: The bark stopper can automatically detect dog barking from 50ft away, and emit a safety ultrasonic that only dogs can hear to prevent and train you or your neighbor's dog to stop barking. 5Adjustable: Dogs with different barking may have different sensitivity to different frequency bands, you can turn the knob to test different frequency bands to get the best results. Item Type: Outdoor Bark Control Device Material: ABS Size: Approx. 8 x 4 x 6cm / 3.1 x 1.6 x 2.4in Battery Type: 1 x 9V Battery (Delivered without Battery) 1 xOutdoor Bark ControlDevice 1 xEnglish Manual 1. Humans cannot hear ultrasonic but precautions should be taken when preparing to use outdoor bark control.2. When you install, install or hang an outdoor barking control device, you should keep an arm's distance from the human ear to avoid damage to human hearing when the dog starts to bark.3. When the outdoor bark control device is turned on, people should also avoid standing too close to it.4. Not for use by children.5. The electrode of the battery installation part in the product is loosely designed to facilitate the installation of the battery, which is not a product quality problem.6. Manual measurement, please allow 0.40.7in error.