●Include 2 pack triangular prism, the measurement is 6 inch long, the triangle side length is 1.38 inch, decent size easy to take along. ●Made of lead free K9 optic glass, very clear and pure, no bubble and foreign material on the surface. ●Use this equilateral prism to split a beam of light into its spectral components, the color of rainbow, a wonderful gift for friends and teachers. ●A great tool to take your photos with unique effects by the prism without photoshop, adding different touch to your pictures. ●A funny and great way to help kids and students learn about light refraction with interesting observation and exploration.