With these Lazer Trip Wires you can set up an invisible perimeter to alert your of any unwanted invasions of your “space”. The devices don’t actually use real laser beams (hence the spelling ‘lazer’), but use infrared beams to create an invisible trip wire that sets off an alarm when anyone crosses it.

The kit comes with three devices, one main and two secondary units that each send and detect a beam. You can set up two that point at each other or all three or more to create a perimeter. Each has an adjustment to compensate for the ambient light and once armed a voice indicates “System Armed”. When any of the infrared beams are broken an audible alarm is triggered alerting you of the security breach.

The Lazer Trip Wire kit also comes with a misting bottle that you can use to show the beams, just like in the movies, so you can avoid setting them off yourself. Each device requires two AAA batteries and the whole set retails for just under $20 from ThinkGeek.