Description : 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. Specificatio ns : Material: Plastic base, high-quality optical glass prism Color of Base: Black Size: 8 x 2.5 x 16cm Weight: 100 g(approx.) Instruction: Put prism under sunlight. Rotating prism till light appear seven colors on a wall or white paper . Package Includes: 1 x Optical Pri sm . Note: Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering.