Check the listing for details. Equilateral Prism, 2" x 1" - Glass - For Optical Experiments - Eisco Labs. Condition: New. Listed at 11.49 USD. Equilateral Prism, 2" x 1" - Glass - For Optical Experiments - Eisco Labs Equilateral prism made of glassPrism measures 2" (50mm) long and each face measures 1" (25mm)Will create a rainbow with any standard light source (led from a phone will work)Designed for physics and educational uses. Because of their educational use design, there may be minor imperfections that do not affect physical functionGreat for photography lighting effects Equilateral prism, made of quality glass. Excellent tool for optical experiments. Prisms will create a nice rainbow (even in room light) by using the simple led light of a smart phone (such as an iPhone). User will need to create a small slit in a black piece of paper and use that slit in front of the led which will create a light ray. The prisms will then refract the white light and create a nice rainbow on a target away from the prism. The farther away you move the target the bigger the rainbow gets and the more distinct colors the user can see. A great tool for teaching optics or for just having fun. This equilateral prism measures 2" (50mm) long and each face measures 1" (25mm). Product Details Brand Eisco Product Type Prisms MPN PH0554HG Check out my other items.