This equilateral acrylic prism measures 25mm in length with 25mm faces. Made from optical quality acrylic polished on all faces with a refractive index close to optical glass. Can produce a rainbow from a non-monochromatic light source such as sunlight. The acrylic construction will not break or chip like glass but is a softer material that should be handled carefully to prevent scratching. Suitable for student physics classrooms studying refraction principles and light dispersion.