The main thing the Crystal Optical Glass Triangular Prism is splitting beam of light into different spectral components and to form rainbow. Good stuff that helps kids learn about optics and light spectrum. Perfect classroom uses as well as home, wedding, party decoration. Make the most out of sunlight with our high clarity crystal glass triangular prism. It also comes with a gift box since the crystal prism is very fragile. Dimensions: 3.4*0.6*0.6 inch (15*15*87 mm)