Mini Voice Stress Analyzer. Battery powered and can be used anywhere. Built-in microphone analyzes ‘the voice’ acoustically (range up to 5 meters). The read-out is given by 12 light-emitting diodes: green indicates ‘normal’ condition, the led diodes indicate ‘stress’ – attention! This, like a heartbeat, is involuntary, the speaker can neither evoke nor suppress this effect. The supplied suction cup can be connected to any (wired) phone analyzing ‘lies’ during phone calls! For more information we refer to page 92 of our Catalogue in which you will find an extensive scientific description of this product