[Anti-Barking Of All Sizes And Breeds] Anti barking device has 3 adjustable sensitivity and frequency levels (Ultrasonic dog bark control has 3 adjustable sensitivity and frequency levels (low(15ft), medium(30ft) and high(50ft)) to help you choose different waves and handle different waves easily barking. Adjust the training frequency every week to maintain the training effect. [Upgraded Dog Training & Behavior Aid Tool ] The ultrasonic dog barking deterrent penetration range is 50ft, covering indoor and outdoor areas. Compared to traditional dog trainers, it completely frees your hands. You can easily train your dog's behavior by turning on the knob. Tested for best results within 50 feet. The smaller the range, the better the effect. 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 for Dogs & People] Ultrasonic bark stopper will not cause interference or harm to humans because humans cannot hear these frequency bands, but dogs are sensitive to these ultrasounds. Different dogs may be sensitive to different frequency bands of ultrasound. Some dogs may be afraid or dislike the sound and won't stop barking at first, so turn the knob to test different frequency bands for best results. [Weatherproof and Durable] Anti bark device is waterproof and durable enough to withstand any weather conditions; making it a great dog barking deterrent for controlling your dog. Runs for up to 1 month on a 9-volt battery (not included) depending on use. [Using Friendly Tips] Anti bark device is not suitable for the following: aggressive dogs, noisy environments, hearing impaired dogs, multiple dogs together, dogs under 6 months or over 8 years old.