Lens material: ABS. Preferred material, good quality, safe, durable and functional. Batteries required: 2 AAA batteries (not included)<br> Three-way linear : The direction of the light can be adjusted with a screwdriver.<br> Optical experiments: refraction of light, convex lens refraction, lens refraction, prism refraction, plane mirror reflection, diffuse reflection, convex mirror reflection, concave mirror reflection, etc.<br> Physical Optics Experiment Set: Will give your child a understanding of physical optics, making learning easier and more enjoyable!<br> Name: Optical Experiment Kit<br> Colour:White<br> Material:ABS<br> Size: 24 x 14 x 3cm<br> Package Contents:<br> 1x 3 Times Bi-Convex Lens<br> 1x Single Concave Lens<br> 1x Acrylic Glass Brick<br> 1x Single Convex Lens<br> 1x Double Concave Lens<br> 1x Triangular Prism<br> 1x Three-Way Linear<br> 1x Multifunctional Reflector<br> Only the above package content, other products are not included.<br> Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.