With the LED ultrasonic dog trainer, you can train your pet to be obedient, corrects misbehavior, and stops barking. You can effectively train your dogs to be obedient, such as barking, digging, chewing, and more. It can activate visual and additive activation to dogs, cats, and other animals. They are harmless to both humans and pets. It is portable and handheld, also convenient for you to carry anywhere you need, such as jogging or walking, cycling, park and so on. If the light gets dim, please change the batteries.timely.The battery is not included in the package.