Large optical prism with a base is very convenient to change prism angle. It can be used in science class of kindergarten, primary school, high school, as a demonstration equipment, to study the dispersion of light. It also can be used as toy to Develop intelligence of children.Features:1, Very convenient to change prism angle.2, Can be used for teaching light spectrum physics.3, Used in science experiments involving light spectrum.4, Precise cuttings, offer good reflections and light separation.Specifications:Material: Plastic base, high-quality optical glass prismColor of Base: BlackSize: 8 x 2.5 x 16 cmWeight: 100 g (approx.)Instruction:Put prism under sunlight. Rotating prism till light appear seven colors on a wall or white paper.