LED Ultrasonic Dog Repeller-Trainer is portable multifunction device. You can use is to repel the dog, train the dog or even just for as flashlight. Best device to carry while walking, jogging or patrolling etc.  Put it in your pocket or bag to avoid an unknown dog. The ultrasonic transmitter can be use to train the dog as well. Ultrasonic wave reaches up to 125db which are safe to human ears. Prevent yourself from aggressive dog or wild wolf.