One thing to keep in mind is the alarm may be viewed as getting the attention of trained rescue personnel. All of our SCBA (Self-Contained Breathing Apparatus) have attach to them a PASS device, that will self activate if kept motionless (unconscious/injured firefighter) or can intentionally be activated (firefighter in trouble), it admits a high pitched warbling sound to alert other firefighters. The high-pitched alert device included with this vest would direct rescue personnel to you. Pete