Description:Position single slit in holder on cross-carriage in laser beam to obtain diffraction. Pattern can be shown on a distant screen, or the small screen shown in the picture. Magnification with the cylindrical lens can be used as necessary. One slide with four slits is available: 0.2mm, 0.04mm, 0.08mm, and 0.16mm, as well as individual slides of 0.12mm, 0.25mm, and 0.5mm.