Dog Bark Control and TrainingThe anti bark device uses the latest ultrasonic technology which is suitable for dogs of all breeds and all sizes. Stop excessive, noisy dog barking by emitting an ultrasonic sound to silence the dog. The anti barking device with four adjustable ultrasonic volume levels - test, low, medium, and high,Please turn the knob to test different frequency bands to obtain the best results. Safe for Dogs and HumanMost humane and used widely way to keep your own dog or your neighbors dog from barking. 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. However, some dogs may be afraid or dislike this sound and will not stop barking at first, so please allow up to 2 weeks for training. Effective and PowerfulThe New Bark Controller come with a well-designed cute shape. The range of ultrasonic penetration is 50ft, covering the area indoor and outdoor. Designed for easy hanging or mounting on a tree, wall or fence post to stop any dogs barking (within range).Compared with the traditional dog training device, it completely frees your hands. (If placed indoors, should the sensitivity be adjusted to 1). Durable and WeatherproofOur anti barking device is waterproof and durable, it can withstand any weather conditions making it an excellent outdoor bark control for dogs.Operates 9-Volt batteries (not included) and will last up to 1 months depending on use. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-YJL official store