Product name: Large optical bench Product Type: Optical Experiment Product use: Convex/concave lens imaging method/determination of focal length Structure: removable Product weight: 1.8KG Product size: 12 * 96cm Include: Large optical bench*1 Light source *1 White screen*1 1 word screen*1 Plastic Frosted Glass Screen*1 Plano-convex lens *1 Double concave lens *1 Double convex lens *2 Candle holder*1 Brightly plated metal rod*5 Tip: If you have any questions about the product, you can write to us and we will answer your questions as soon as possible