This hand held unit is both attractive and lightweight, giving you a humane weapon to train your dog, or to fend off hostile dogs, as well as an alarm to repel other attackers. Designed to fit comfortably in your hand, or clipped on a belt, Dog Off also features a handy flashlight. At the touch of a button, it will transmit a burst of ultrasonic sound (inaudible to humans) to help train your dog's behavior. Hold the button down, and a high pitched ultrasonic siren (inaudible to humans) that can repel dogs away. Pull the personal alarm switch to set off a loud and audible alert that will send human attackers fleeing. Ideal for joggers, repairmen, postal delivery workers, and outdoor enthusiasts. Also great for training your dog.