Optically Worked Double Convex Glass Lens, 75mm Diameter, 100mm Focal Length Entomology & Zoology_Zoology Charts & Models and a dual-scale screen

and a dual-scale screen

and acrylic in a foam-lined wooden case for density-versus-material investigations

plus a removal tool in a 4-compartment storage box

5-inch stainless steel connecting rod

25mm enameled copper wire on a 355 x 50mm air-cored former with 4mm safety sockets and a 6A maximum

Optically Worked Double Convex Glass Lens, 75mm Diameter, 100mm Focal Length Entomology & Zoology_Zoology Charts & Models and a dual-scale screenOptically worked double convex glass lens at 75mm diameter and 100mm focal length, the f 1. 3 geometry favoring strong convergence and bright real image formation across a wide aperture.