fficient Ultrasonic Barking Control Device: Updated ultrasonic dog bark deterrent makes you handy when training your dog. 3 ultrasonic frequency levels cover the training of most dogs. The time you turn on the bark control device, it will automatically detect the dog's barking and emit ultrasound. Once the dog keeps quiet, the Ultrasound will stop automatically. 100% Safe for humans and Fit with Dogs: The ultrasound will not cause any interference or harm to humans, because human cannot hear these frequency bands, but dogs will be sensitive to these ultrasounds. Different dogs may be sensible to ultrasound of different frequency bands. Please turn the knob to test different frequency bands to obtain the best results. Range up to 32ft Anti Barking Device: The range of ultrasonic penetration is 50ft, covering the area indoor and outdoor. Compared with the traditional dog training device, it completely frees your hands. You can easily train the dog's behavior by turning on the knob. After testing, the best effect is within 50ft. The smaller the range, the better the effect. Durable power & Waterproof & Easy to Install: Equipped with a powerful battery, the anti-bark device can contiguously work for 30 days after fully charged. IPX4 waterproof can be hung on the tree, anywhere indoors, outdoors and so on. Warm Tips for Usage: The dog deterrent device is not applicable to the following situations: aggressive dogs, noisy surroundings, hearing-impaired dogs, two or more dogs together, dogs under 6 months or over 8 years.