Product Power: 1 x 9V battery (not included)Dog barking control devices is like dog whistles that makes dogs stop barking. The dog bark deterrent devices are automatically activated by the sound of barking. When the device is within the range of a barking dog, it will emit an ultrasonic sound to silence the dog.Features:1. Use ultrasound to prevent dog barking, effective range 50 feet2. Easy to use and test, four levels of operation range (including test mode)3. Durable, suitable for outdoor use4. Dry battery power supply, low battery indicator5. The ultrasonic dog bark deterrent could be hung on the tree, anywhere in the house or in your yard, it can be hung, placed on the table or other places at will.Specification:Item Weight: 350g (color box included)Color Box Dimension: 17*13.5*13.5cmMaterial: ABS plasticPower: 1 x 9V battery (not included)Package includes:1Stop Dog Barking Device1User Manual in EnglishNote:1.LED light flashes for low battery indication.2.No bark bird box will not work on deaf or hearing impaired dogs.3.Human cannot hear the ultrasonic sound, however precautions should be taken when preparing the outdoor dog bark control for use.