Double Concave Lens, 500mm Focal Length, 3" (75mm) Diameter - Spherical, Optically Worked Glass Lens - Ground Edges, Polished - Great for Physics Classrooms - Eisco Labs auspowers_batchthree can be stuffed with clothing

can be stuffed with clothing to create a makeshift pillow on fast-and-light adventures

it is oblate and has small volume

50mm Dial (B61310-5700)

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Safe to be used for adults & children

Double Concave Lens, 500mm Focal Length, 3" (75mm) Diameter - Spherical, Optically Worked Glass Lens - Ground Edges, Polished - Great for Physics Classrooms - Eisco Labs auspowers_batchthree can be stuffed with clothingDouble Concave Lens, 500mm Focal Length, 3" (75mm) Diameter Spherical, Optically Worked Glass Lens Ground Edges, Polished Great for Physics Classrooms Eisco Labs Product Features DOUBLE CONCAVE Highly polished, double concave lens SPHERICAL Lens measures 3" (75mm) in diameter 500MM FOCAL LENGTH Diverging lens with a 500mm focal length OPTICALLY WORKED GLASS Made of high quality, optically worked glass. Highly polished with ground edges GREAT FOR