Students can clearly see a 3-D image of a magnifying lens in front of a telephone and observe the effect of the lens as if it were really present in this large 20 x 25cm transmission hologram. It is protected on both sides by glass panels. It can be used for individual viewing, in a classroom demonstration, or a school display. Any low power He/Ne laser can be used to project a real image or view the virtual image. Includes an instruction booklet.