Tips:
1. Please note that the whistle of this product is not ultrasonic and can be heard by human ears.
2. We believe that reasonable training should be used to prevent dogs from barking. Our details page has introduced some of them. Our products have the function of auxiliary training, but they cannot directly stop dogs from barking.
3. We do not approve of using the so-called ultrasonic whistle to stop the dog from barking, because it will cause negative disturbance to the dog.