The Anti Barking Device is an upgraded training and behavior aid tool for dogs. Using the latest ultrasonic technology, it emits a high-pitched tone that only dogs can hear. When the device senses the dog's barking, it automatically emits ultrasonic waves. Once the dog stops barking, the device stops emitting the waves. This device is suitable for dogs of all sizes and breeds. It offers 4 sensitivity levels, allowing you to customize the settings based on your environment and the dog's behavior. You can adjust the induction distance and sensitivity to achieve the best results. Level 1 is the least sensitive, while level 4 is the most sensitive. The Anti Barking Device is safe for both dogs and humans. It does not use electric shocks, irritating smells, or beeping sounds. Instead, it sends out ultrasonic waves to stop the dog from barking. This creates a quiet environment for you, your family, and your neighbors. Please note that the device may not work as intended for dogs that are hard of hearing or aggressive. This device is USB rechargeable and comes with an indicator light. It can be easily used and recharged. A 5-hour charge provides 30 days of use, eliminating the need for constant battery replacements. The device is ready to use right out of the box, but it is recommended to fully charge it before use for better effectiveness. With a range of up to 32 feet, the Anti Barking Device is effective for both indoor and outdoor use. It allows you to train your dog's behavior without the need for traditional dog trainers. Simply turn on the knob to start training. It is also great for stopping neighbors' dogs and homeless dogs from barking outdoors. Key Features: Latest ultrasonic technology 4 sensitivity levels Safe for dogs and humans USB rechargeable Effective indoors and outdoors