NO MORE ANNOYING BARKINGThis bark deterrents uses ultrasonic sound wave to effectively trains your dog to stop excessive, noisy barking. Suitable for all sizes and breeds of dogs. 3 LEVELS ULTRALSONIC & 50 FEET EFFECTIVE RANGEWith a built-in microphone and 3 levels ultralsonic intensity, which can detects dog barking from 50 feets away. Pleaes use the test mode to verify the microphone and speaker are working properly. SAFE MATERIAL FOR HUMAN & PETSWe cannot hear the low-intensity ultrasonic sound wave, it only work for dogs, which is convenient and unharmful.You can enjoy a quiet night with this anti barking device. Effective for most dogsSuitable for dogs of all breeds and sizes, but not for dogs with hearing loss or hearing loss. Open the outdoor bark control only during unnecessary barking to prevent the dog from becoming desensitized. LOVELY APPREARANCEThis birdhouse-shaped sonic bark deterrent can be mounting on a tree, wall or fence to keep your own dog or your neighbors dog from barking. Pls make sure the microphone is less than 5 feet high and is facing the direction of the barking dog.