【3 Adjustable Modes & Range Up to 50Ft】Dog barking deterrent device has 3 adjustable levels (15FT-50FT). Different dogs may be sensitive to ultrasound in different frequency bands. Please turn the knob to test different frequency bands for best results. If you or your neighbor's dog barks too excitedly, put it in the right spot, and you'll have a quiet resting environment. 【Safe & Friendly Anti Barking Device for Dogs】Ultrasonic bark control device will not cause any interference or harm to the human body. The ultrasonic frequency emitted by the ultrasonic barking controller is within the average hearing range of a dog. Other family members or neighbors will not worry about being affected. It does not cause major punishment to the dog, it emits an ultrasound that only dogs can hear to get its attention. 【IPX4 Waterproof Barking Box】Barking dog deterrent has an IPX4 waterproof rating, and the shell is UV-resistant and not easy to fade. Whether it is windy, rainy or snowy, our no barking device for dogs can withstand bad weather and still work properly. The dog barking silencer is small and convenient, and can be used safely indoors, outdoors or anywhere else.