Great for presentations with 50-100 people 3000-lumen light output allows easy viewing of presentations. Great for use in medium-sized classrooms or meeting rooms. High/Low lamp brightness control adapts projector to brighter or darker rooms and helps extends lamp life. Double Fresnel lens assures edge-to-edge sharpness and brightness. Closed-head design helps prevents damage to mirror and lens. Keeps dirt, dust and foreign objects away. Large (11.25in. x 11.25in.) stage glass lets you see transparency sheets from edge to edge. Lamp changer switch allows you to recover instantly from a lamp failure. Lets you switch to an alternate lamp by simply flipping a switch. Kensington Security Slot helps protect against theft. Allows you to secure projector by means of a locking cable (sold separately). Apollo(R) 3002M Closed-Head Overhead Projector is one of many Projectors available through Office Depot. Made by Apollo.