Periscope Is An Instrument For Observation From A Concealed Postion. In Simplest Form It Consists Of A Tube With Mirrors At Each End Set Parallel To Each Other At 45-Degree Angle. Tanks, Sub Marines Use Periscope Extensively. They Enable Drivers Or Tank Commanders To Inspect Their Situation Without Leaving The Safety Of Tank Or Marine. This Kit Helps Student To Make Real Periscope And Scan The Horizon Without Being Seen. Its A Unique And Fascinating Spying Toy Which Also Teaches Scientific Principles.