AHANDMAKER 5 Pcs Physical Optical Experiment Set, Acrylic Lens and Prism All Faces Fully Polished for Lab Supplies Physics Teaching (Double Concave, Double Convex, Rectangle, Semicircle)

I bought this set because it had the assortment of mirrors and lenses I needed for a high school physics lab, and it was cheap. I bought another more expensive one at the same time, figuring I would probably have to return this one due to poor quality.Low and behold, this set actually produced better results for demonstrating reflection and diffraction with a laser pointer. True, they are quite small, about the length of my pinky, but they get the job done, and for the price, this is a great value for classroom demonstrations.