Spectrum tube Power Supply, Connecting sockets are fully shielded to prevent electric shock. The bottom socket is spring loaded so tubes can be changed easily. Operates on 220V. The cord is 8 inch. Overall dimensions: 14-1/2inch x 4-1/2inch x 3inch
Double Convex round Lens, Material: Glass, designed for physics and educational uses, Because of their educational use design, there may be minor imperfections that do not affect physical function, for educational uses, Size: 50mm focal length, 2in diameter and 3.5mm thick
Double Convex Lens, Highly polished, optically true lens is excellent for physics classroom demonstrations in optics and light refraction, with ground edges, great for physics classrooms, with highest grade, Size: 100 mm focal length, Lens measures 3in diameter, 0.3 weight
Double Convex Lens, Highly polished, optically true lens is excellent for physics classroom demonstrations in optics and light refraction, with ground edges, great for physics classrooms, with highest grade, Size: 250 mm focal length, Lens measures 3in diameter, 0.2 weight