A motor vehicle's horn, bell, siren
or other sounding device that is easily audible at 300 feet. Some alarms have an automatic shut-off and reset
capability that provides for the alarm to sound for not more
than four minutes, shut off and then immediately rearm
itself. Other alarms have a backup battery which is an
auxiliary power source that trips an alarm device if the
main power source is disconnected or if the wires to the
alarm device are cut or disconnected.