dog training,dog barking control devices,anti barking device,dog training clickers,dog whistle to stop barking,bark box,barking control devices,dog barking deterrent,pet supplies for dogs Safe For Dogs And People The ultrasound will not cause interference or harm to human, 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. Dog Bark Control & Dog Training Anti barking device uses the latest ultrasonic technology which is suitable for dogs of all breeds and all sizes. The barking control device automatically emits high-pitched sounds that only dogs can hear. Once the dog stops barking, the ultrasonic bark control automatically stops emitting ultrasonic sounds. Durable & Weatherproof Anti Barking Controller come with a well-designed mini shape. Equipped with a powerful battery, the anti bark device can contiguously work for 30 days after fully charged. Designed for easy hanging/mounting on a tree, wall or fence post to stop any dogs barking (within range), anywhere indoors, outdoors and so on. Effective & Powerful 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. If your or your neighbor's dog is barking too excitedly, put him in the right place and you will have a quiet resting environment. Warm Tips for Usage The dog deterrent device is not applicable to the following situations: aggressive dogs, noisy surroundings, hearing impaired dogs, more dogs together, dogs under 6 months or over 8 years.