Double Concave Lens, 50mm Focal Length, 2" (50mm) Diameter - Spherical, Optically Worked Glass Lens - Ground Edges, Polished - Great for Physics Classrooms - Eisco Labs home2022 place the board on the

place the board on the two brackets

it has no elasticity

of non ferrous metals (aluminum

and other sewing craft

Warm Company Steam-A-Seam 2 Double Stick Fusible Web-9"X12" Sheets 5/Pkg (5517) (2-Pack of 5)

Double Concave Lens, 50mm Focal Length, 2" (50mm) Diameter - Spherical, Optically Worked Glass Lens - Ground Edges, Polished - Great for Physics Classrooms - Eisco Labs home2022 place the board on theDouble Concave Lens, 50mm Focal Length, 2" (50mm) Diameter Spherical, Optically Worked Glass Lens Ground Edges, Polished Great for Physics Classrooms Eisco Labs Optically True, Double Concave Lens50mm Diameter, 50mm Focal LengthHigh quality, optically true lens. Made of highly polished, quality glass. Spherical with ground edges. Designed for educational purpose and science classroom demonstrations in optics and light physics. Lens measures 2" (50mm)