YOKIVE Double Concave Lens, Clear Glass Optical Lenses | Make Telescope, Great for Photography, Optical Instruments Use (Clear, 150mm Focal Length)

YOKIVE Double Concave Lens, Clear Glass Optical Lenses | Make Telescope, Great for Photography, Optical Instruments Use (Clear, 150mm Focal Length)

EISCO 6pc Optical Lens Set, 2" (50mm) Diameter - 3 Double Convex Lens & 3 Double Concave Lens - 200mm, 300mm, 500mm Focal Lengths - Optically True Glass - Ground, Beveled Edges

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