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

Eisco Labs 6 Piece Premium Optical Glass Lens Set, 50mm Diameter - 3 Double Convex (20, 30, 50cm FL) and 3 Double Concave (20, 30, 50cm FL)

Eisco Labs Optical Glass Lens, Double Concave, 75mm Diameter, 20cm Focal Length - Ideal for Top Spinning

United Scientific LCV108 Glass Double Convex Lens, 100mm Diameter, 200mm Focal Length

Eisco Labs Double Concave Glass Lens, 75mm Diameter, 30cm Focal Length

Amlong Crystal 6 inch Optical Glass Triangular Prism for Teaching Light Spectrum Physics and Photo Photography Prism, 150mm

American Educational 6 Piece Glass Lens Set

A&M Film and Photo Photography Prism - Professional Grade Optical Crystal Glass for Taking Amazing Pictures

Eisco Labs Double Concave Glass Lens; 75mm Diameter; 300mm Focal Length

Elkhart Products 101 1-Inch Copper Couplings without Stops

UEETEK 10cm Diameter 300mm Focal Length Double Convex Glass Lens For Labs Experiment