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: 200 mm focal length, Lens measures 3in diameter, 0.1 weight
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: 200mm focal length, Lens measures 3in diameter, 0.2 weight
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: 250 mm focal length, Lens measures 3in diameter, 0.2 weight
Pulley Large Demonstration Single, Designed for Classroom Demonstrations, Light-weight, low-friction, and deformation-resistant plastic ensures accurate results, Open to make it easier for users to run pulley cords through them