Double Convex Lens, Highly polished, optically true lens is excellent for physics classroom demonstrations in optics and light refraction, with ground edges, great for physics classrooms, with highest grade, Size: 500mm focal length, Lens measures 3in diameter, 0.1 weight
KidWind simpleGEN, easy-to-build AC generator that allows students to explore the basics of electrical generator design, Recommended for College, High School, and Middle School Science