The Model 1608 may be low in cost, but it is packed with the features you need to deliver clear, bright images in your classroom presentations. The extra sturdy construction delivers years of reliable use. OPTICAL PERFORMANCE Head: Open singlet (one element) > Illumination: 2,000 ANSI lumens typical Stage aperture: 285.75 mm x 285.75 mm (11.25" x 11.25") > Stage temperatu