From the Artograph Website:

The Super Prism® is designed for the artist or designer who needs the best in image clarity and accuracy. Ideal for working from a variety of challenging originals like photographs, half tones, and highly detailed drawings. Features a 3-element, color-corrected lens for extra sharp images and increased brightness. This Super Lens enlarges originals from 2 to 20 times. Includes extra accessory lens to extend the range from 3 times enlargement down to 20% reduction. *Includes 500-Watts of photo quality lighting for a whiter and brighter image (2x 250-Watt bulbs). Magnetic door latches and a spring clip keep copy securely in place. Generous 7 x 7 inch (177.8 x 177.8 mm) top-loading, glass covered copy area makes for easy placement of large copy, books, or small 3-D objects. A fan cooling channel system and thermal overload circuit protect originals from overheating. Dark room required.

The unit has been tested and both lightbulbs work and both lenses project a clear image. If you have any questions please contact me before purchasing, thank you.