Build Your Own Lie Detector Stay calm! Don\'t panic! You\'ll need nerves of steel to pass this terrifying test. Put your family and friends in the hot seat with your very own self built lie detector. Watch them squirm and sweat as you get straight to the point, interrogate with the questions you have never dared to ask before! Once assembled, turn the ON/OFF switch all the way ON. With user one facing the lie detector gauge, user two asks a question. User one then places two fingers on the sensor pad. 0 = Low (Truth), 9 = High (Lie). Included is a card outer body which will need assembling, electronic components and instructions.It requires a 9V battery and double sided tape (not included). Please note: the touch pad is very sensitive and direct pressure with fingers in the centre of the metal contacts will cause the needle to swing fully to the right. For best results it is advised to apply light pressure near the edge of the metal pads. This way any increased pressure applied through nerves will cause the needle to slowly move to the right and point towards a lie.