Ultrasonic Dog Repeller Dual Channel Anti Bark Device 3 in 1 Dog Training Tool with LED FlashlightUltrasonic dog repellent: Produces very powerful ultrasound. When the dog hears the ultrasonic sound, it will become uncomfortable and therefore away from people. People can't hear it.Dog training equipment: it can effectively stimulate the dog's nervous system, so that it can be guided by the owner, there are infrared lights , you can let the dog follow, you can train your pet by your personal hobbies.Dimensions: 13.5 x 5.5cmPortable: Comes with a lanyard, convenient to carry anywhere you need, such as jogging or walking, cycling, park and so on. Easy to use: open the battery cover first, then put in 1 x 9V battery (not included), turn on the switch and it can work well, they can also be used as a flashlight if necessary.Note: The data is all measured manually, please allow 1-3cm error, due to the difference in light and display, there will be a certain color difference , the actual object received shall prevail.