1. ULTRASONIC ANTI BARKING DEVICE FOR DOGS: This anti dog control device uses ultrasonic technology to intervene in dog barking. When the microphone of the antibarking device picks up a barking dog, the speaker automatically emits an ultrasonic wave to the dog to stop barking. 2. 3 ULTRASONIC SPEAKER MODES: Our ultrasonic bark stopper is equipped with 3 ultrasonic speakers and has three adjustable modes, Mode 1: 15 30 KHZ for naughty or large dogs. Mode 2: 20 KHZ for docile dogs. Mode 3: 30 KHZ for small dogs. 3. SAFE AND FRIENDLY BARK BOX: Our antibarking device only emits ultrasonic waves when the dog barks to stop the annoying barking, and it will not cause any harm to dogs. They are inaudible to humans and have no impact on humans. 4. RECHARGEABLE DOG BARKING SILENCER: Our dog barking silencer features a TypeC port for convenient charging. The sturdy ABS and waterproof shell gives the stop barking device a longer lifetime and can be placed or hanged everywhere.