【Up to 50 Feet Range Anti-Bark Device】 The sonic penetration range is 50 feet, covering both indoor and outdoor areas. Compared with traditional dog training devices, it completely frees your hands. You can easily train your dog's behavior by turning the knob. After testing, the best effect is within 50 feet. The smaller the range, the better the effect. 【Effective on Most Dogs】 The device works on most breeds and sizes, but not on deaf or hard-of-hearing dogs. Some dogs may be afraid or dislike the ultrasonic sound, and they will not stop barking at first. Please allow up to 2 weeks for training. 【Safe Barking Stopper】 The sonic is harmless to pets. If the dog is hard of hearing or aggressive, the device may not work as expected. Using one device against two or more barking dogs at the same time is not recommended. 【Easy Installation & Waterproof】 The device is designed to be easily hung or mounted on a tree, wall, or fence post to prevent your own or your neighbor's dog from