[Effective Dog Bark Control] - Newly upgraded chip that stops excessive and loud dog barking by emitting an ultrasonic sound to silence the dog. More effective than older deterrent versions 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 if microphone and speaker are working properly. [100% Harmless] - It emits high frequency ultrasonic to make dog feel uncomfortable and stop barking instead of hurting dog, no effect to dog's health. And is completely inaudible to humans, so it is absolutely safe. [Waterproof and Durable] - The bark 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 bother. to bark. On the other hand, it will also be a good helper to train 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 insensitive. Powered by 9V battery operation (NOT INCLUDED).