1.Multifunctional design: this antibarking device is compact in shape and beautifully designed to hang from trees, indoor or outdoor walls or fence posts to stop any dog barking within range. It also comes with four buttons, including a test button, an off button and three level buttons, making it very easy to use. 2.Effective Barking Control: Our ultrasonic dog antibarking device helps you and your neighbors get rid of noise by emitting 20KHz25KHz ultrasonic waves to correct your dog's bad behavior and effectively prevent your neighbor's dog from barking. No need to use a collar, suitable for all breeds and sizes of dogs, and practical. 3.Wide effective range: This bark control device has multiple settings and a multidirectional microphone to capture dogs in any direction. It has three modes including low range (up to 15 feet), medium range (up to 30 feet) and high range (up to 50 feet) to effectively control your dog's barking within a 50foot range. 4.Small and : This ultrasonic antibarking device is small and and has been tested and proven to be harmless to humans, animals and plants. It emits a sound that is effective for dogs but cannot be heard by humans. It is for small, medium and large dogs.