Description Appropriate size: Portable dog trainer measures 13.7 x 5.5 x 2.5 cm / 5.39 x 2.16 x 0.98 inches; small size, doesnt take up space, light to carry; fits in your pocket and hold it when you need it; High quality material: the material of this handheld dog trainer is plastic, safe and reliable, not easy to carry and tear, durable and can be used for a long time, repel the dog barks for you, but not harmful for the dog. Ultrasonic anti-bark: this portable dog trainer uses ultrasonic technology; it produces ultrasonic waves when applied; the ultrasonic frequencies will prevent your dog from barking; suitable for all breeds and sizes of dogs; sound frequencies are safe for pets, not for human ears. but dont apply it for too long, it may have no effect on the dog Easy to use: first open the battery cover, then insert the 9V battery (not included), turn on the switch, it can be used to train the dog, as long as the battery is charged, it can work normally, and it can be used as a torch if needed MULTIPLE USES: This portable dog repellent trainer uses a gentle way to warn dogs not to bark; it can be used as a dog repellent and dog training aid to prevent bad behavior Dogs like endless barking, digging and fighting, etc., can give you a calm environment, prevent animal barking and disturbing neighbours.