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
Equilateral Prism, Material: optical glass, Perfect for optical refraction experimentation, Will create a rainbow with any standard light source (led from a phone will work), Because of their educational use design, do not affect physical function, Size: 75mm lengthx25mm face size