Rectangular Block - Glass, Made from imported optical glass with optically worked surfaces, All angles accurately worked with edges slightly bevelled and glass free from bubbles, Size 75 x 50 x 12 mm
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 1.5in diameter, 0.2 weight