Dog Bark Control and Dog Training - Our ultrasonic barking control devices provide a safe and effective solution for dog training and bark control. The anti bark device can effectively train your dogs to stop unwanted behaviors such as barking, digging, eating unsafe food, fighting, etc. Suitable for All Size Dogs - The average human hearing frequency range is 20HZ~20KHZ, and the dog can hear a wider range from 15HZ to 120KHZ. The ultrasonic bark control emits ultrasonic sound at 25KHZ, so the sound doesnt affect humans, but can grab dog's attention. Convenient to Use Outdoor - The ultrasonic dog barking deterrent devices just fit nicely in your hand and comes with an adjustable anti-static wrist strap. The control range of the bark deterrent is 16.4ft. As we use ultrasonic technology, it works effectively on all sizes of dogs. Easy to Use - When you press & hold the button of the ultrasonic barking control devices, it will emit an ultrasonic sound that can only be heard by dogs. The LED indicator lights up green when the device is working and emitting ultrasonic sound. Press the button for over 10 seconds, the barking control devices will be turned off automatically. The device is powered by 4 AAA batteries (not Included). Users Guidance - The ultrasonic anti barking device doesn't effective in dogs with hearing problems and we dont recommend using this product on dogs under six months or above 8 years old. Training is required to achieve highly effective and long-lasting use.