Multifunction: The anti-bark device is versatile. You use the ultrasonic trainer to train the dog, to drive away the bad dog in a humane way, and to protect your personal safety. The anti-bark device is equipped with LED lights to help with nighttime illumination and is suitable for outdoor workers. Ultrasonic design: Hand-held dog repellent bark uses ultrasonic sound to effectively protect the dog train and make the dog do what you want while preventing the dog from scratching, attacking, barking and other bad behaviors. The trainer reduces noise when training the dog. Easy to use: The dog trainer is easy to use and suitable for everyone. You need to open the cover, insert the 9V battery (the product does not contain the battery), press the switch button, the bark discharger can be used normally. The operation is very simple. Convenient to use: The anti-bark stopper is very easy to carry, has a size of approximately 1.57 x 4.9 inches and fits most people's palms. You can take it anywhere you need, such as parks, walking, jogging, etc. The size of the trainer is perfect.