As any elite secret agent knows- it*s important to protect your secret headquarters from spies- intruders- or even nosy younger sisters. And now it*s easy with the Spy Motion Alarm- an advanced- motion-sensing security system that projects an invisible beam across doorways and sounds a warning when security has been breached.**Just position the Spy Motion Alarm unit so that it projects an invisible beam across a doorway- hallway or window- and it will sound an alarm when an intruder crosses the line. A beam adjuster allows you to adjust the beam from long and narrow or short and wide. Red LEDs provide a visual alert to let you know the Spy Motion Alarm unit is armed and functioning. 20-ft. range maximum. Requires 2 AA batteries (sold separately).**** * Protect doorways- hallways or windows easily ** * Any motion activates a beeping alarm to make sure your belongings and privacy are protected ** * Detects movement up to 20 feet away