Automatic Dog Bark Control. The device intelligently captures barking dogs from up to 15 meters away and automatically emits ultrasonic sound that distracts your dog to stop unwanted barking. Dog Bark Stopper. Ultrasonic frequencies are harmless to pets and completely inaudible to the human ear. If the dog is hard of hearing or aggressive, the device may not work as expected. It is not recommended to use one device against two or more dogs barking at the same time. Adjustable frequency dog bark deterrent is suitable for different dogs. It is recommended for dogs aged 6 months to 8 years. Rechargeable by USB. The device incorporates a rechargeable lithium battery and can work continuously for 30 days after being fully charged within 5 hours. Red and blue color indicates battery status. Easy and Waterproof Installation. The device can be hung on a tree, wall, or fence. Make sure the bark controller is facing the dog within reach without any obstruction. Condition: New. Origin: China. Please