Lens material: ABS. High-quality, safe, durable, and functional. Batteries required: 2 AAA batteries (not included). Three-way linear: The direction of the light can be adjusted with a screwdriver. Optical experiments: Light refraction, convex lens refraction, lens refraction, prism refraction, plane mirror reflection, diffuse reflection, convex mirror reflection, concave mirror reflection, and more. Physical optics experiment set: Helps children understand physical optics, making learning easier and more enjoyable. Name: Optical Experiment Kit Color: White Material: ABS Size: 24 x 14 x 3 cm Package Contents: 1 x 3 Times Bi-Convex Lens 1 x Single Concave Lens 1 x Acrylic Glass Brick 1 x Single Convex Lens 1 x Double Concave Lens 1 x Triangular Prism 1 x Three-Way Linear 1 x Multifunctional Reflector Only the items listed above are included; other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture to differ slightly from the actual product. Measurement error allowance: +/- 1-3 cm.