True Motion Detection with High Sensitivity (up to 40ft) .    Alarms are set off when the motion sensor detects movement or light sensor is triggered by shadow(s).   It's like 2 devices in one! This shadow detector is equipped with a motion PIR sensor.   The motion sensor can sense movement up to 40 feet away.  The light sensor detects shadows when the device is pointed towards a light source like a laser, flashlight, exit sign, windows, etc.   Anything that gives off some source of light, even low light like a street light thru a window.   When something moves between the light source and the device it will indicate shadow movement was detected.
 
Can be Tripod Mounted
Uses one 9-volt battery
 
VIDEO DEMONSTRATION  (laser used is an example of light source)