Pair of Narrow Prisms

Each acrylic prism is in the form of a narrow isosceles triangles 15 x 60 x 20 mm base, height, thickness. Designed to provide a progression of ideas from the principles of refraction in prism to the properties of lenses. Each acrylic prism is in the form of a narrow isosceles triangles 15 x 60 x 20 mm base, height, thickness. When placed base to base a convex lens may be simulated and a concave lens when vertex to vertex.