Descriptions: Optical Glass Triple Triangular Prism Physics Teaching Light Spectrum 5CM Prism Length: 1.97inch \/ 5cm Side Length: 1.18 inch \/ 3cm Material: Optical Glass Features: Durable and interesting. Show your kids a rainbow. With a decent gift box， it is a good present for friends. It is used to research the refraction and dispersion of the light， and make a thorough inquiry of the forming of the rainbow. Package Included: 1 x 5cm Triple Prism