Made of polished acrylic 15 mm thick, the set is provided in a convenient storage box.
Set consists of: rectangle (75 mm sides), double convex lens and two double concave lenses with a focal length of about 10 cm, equilateral prism, and semi-circular block.
A 75 mm diameter circular metal disc with 12.5 mm central aperture.
A screw controlled spring loaded precision slit is mounted on one side of the disc.
Max opening 4 mm wide and 10-12 mm long.