The 911 Emergency Signal Light is an effective emergency devise that uses section cups to easily attach to the front window of your car, truck, home, or camper. In the event of an emergency simply push the button on the back of the unit to emit a bright flashing strobe light. Tell the police, fire department , or rescue squad to look for the flashing light. They will be able to find your location quickly without having to waste time searching for street numbers. Also great for deliveries or parties.