[Effective Dog Barking Control] - Newly upgraded chip that stops excessive and loud dog barking by emitting ultrasonic sound to silence the dog. More effective than older versions as a deterrent and waterproof. [4 Adjustable Sensitivity] - The anti-bark device has 3 range levels and a test mode. Including: low sensitivity (15 feet), medium sensitivity (30 feet), high sensitivity (50 feet). you can use test mode to check whether the microphone and speaker are working properly. [100 percent Harmless] - It emits high frequency ultrasonic to make the dog feel uncomfortable and stop to bark instead of hurting him, with no effect on the dog's health. And is completely inaudible to humans, so it is absolutely safe. [Waterproof and Durable] - The barking device designed for outdoor use is made of high quality waterproof material. Whether it's a sunny or rainy day, just turn on the switch and you won't have to bark. On the other hand, it will also be a good helper in training your dog. [Effective for most dogs] - Suitable for dogs of all breeds and sizes, but not for hearing impaired or hard of hearing dogs. Open the bark control only during unnecessary barking to prevent the dog from becoming unresponsive. Powered by 9V battery operation (NOT INCLUDED).