[Automatic Dog Bark Stop]The device intelligently captures dog barking from up to 15 meters away, automatically plays an ultrasonic sound that distracts your dog to stop unwanted barking, allowing you to enjoy a moment of peace silence [Dog Bark Stopper]Ultrasonic frequencies are harmless to pets completely inaudible to the human ear If the dog is hard of hearing or aggressive, the device may not work as intended It is not recommended to use a device against two or more dogs barking at the same time [3 Levels of Operation]The adjustable frequency dog bark deterrent device is suitable for different dogs 15KHZ-30KHZ is suitable for big naughty dogs 20KHZ Suitable for gentle dogs 30KHZ Suitable for small dogs It is recommended for dogs aged 6 months to 8 years [USB Rechargeable]The ultrasonic dog repellent built-in rechargeable lithium battery, the device can work continuously for 30 days after fully charged in 5 hours Red/blue color indicates battery status [Easy Installation Waterproof]The anti-bark device for dogs can be hung on a tree, wall or fence to prevent your own dog or that of your neighbors from barking Make sure the bark controller is facing toward the dog within easy reach without any obstruction