Double Concave Glass Lens, 50mm Diameter, 250mm Focal Length, 3mm Thick Material_Wood displayed on a plastic-and-metal rack

displayed on a plastic-and-metal rack with a carrying handle for transport

illustrating molecular symmetry and bonding geometry

Sliding-top wooden box 4 x 2 x 1 inches

sized for low-resistance Ohm's-law work where high-resistance components don't draw measurable current

5 inches) make north and south poles instantly identifiable during attraction

Double Concave Glass Lens, 50mm Diameter, 250mm Focal Length, 3mm Thick Material_Wood displayed on a plastic-and-metal rackSlim 3mm thick double concave glass lens at 50mm diameter and 250mm focal length, the diverging curvature paired with low mass for ray box mounts and lightweight optics setups.