The ultimate spy security system comes with three clamp-on emitter/receiver pods & revealer bottle. The barricade that is formed by lining up the lights from the Lazer Tripwire emitter/receiver pods is invisible to the untrained eye but detectable by an advanced spy who knows the secret of the beam. By spraying a mist of water across its path, the invisible beam illuminates to reveal a bright red line of light. This allows a trained agent to evade the alarm by slithering under or jumping over the active boundary. The beams of the Lazer Tripwire are as safe as a household flashlight.