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: 1000 mm focal length, Lens measures 3in diameter, 0.1 weight
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