Infrared Motion Alarms work by establishing an area of protection. If this area of protection is disturbed or any type of motion is present, the sensors will trigger an alarm that alerts you to the intrusion.
These stand alone motion detection alarms are perfect for specific areas you need to protect. The PIR (passive infrared) sensors will pick up any movement within the detection zone and sound off the alarm.
The auto dialer will even call your cell phone or any other number you program into it when there is a alarm event.