This item is an actual dome surveillance camera that has been modified into a "dummy" or fake security camera.  It is designed to imitate the small, high tech security cameras on the market today.  When placed in your home or business, even the most sophisticated criminals will think the premises are guarded by a high-tech surveillance system and go in search of an easier target.  The dome has a built in motion detector with a range of about three feet; when movement is detected a red LED light will flash for approximately 20 seconds and stop and reset until more movement is detected.  Imagine the surprise a thief will experience when he walks under it and the red LED light starts to flash on the front of the camera.  Installs quickly and easily with the included screws to the wall or ceiling.   The base measures 4 1/2" in diameter and the dome is 3" high.  The unit requires 2 AA batteries that are not included.  Battery life is approximately 12-18 months.  This is also a cheap option for those who do not want a blinking light.  Simply mount the camera without batteries installed.