Round Double Convex Optical Glass Lens - 3" (75mm) Diameter - 100mm Focal Length - 3mm Thick Approx. - Eisco Labs

EISCO Double Convex Lens, 100mm Focal Length, 3" (75mm) Diameter - Spherical, Optically Worked Glass Lens - Ground Edges, Polished - Great for Physics Classrooms

EISCO Double Convex Lens, 200mm Focal Length, 3" (75mm) Diameter - Spherical, Optically Worked Glass Lens - Ground Edges, Polished - Great for Physics Classrooms

EISCO Round Double Convex High Optical Purity Glass Lens - 2" (50mm) Diameter - 50mm Focal Length - 15mm Thick Approx.