A wide array of connectivity options plus PointWrite and QWrite interactive features make the MX823ST a complete classroom interactive projector solution. A short-throw ratio, 13000:1 ultra-sharp contrast ratio, 3200 ANSI lumen brightness and long lamp life ensure vibrant, reliable visual performance time and again. BenQ MX823ST is built with latest DLPR technology to support 3D functionality, allowing schools to bring an immersive learning experience to their students with a simple preparation of 3D glasses and 3D content from your blu-ray player. The upper lamp door is designed for it managers to replace the projector lamp safely and quickly. should the projector lamp go out in the middle of the class, it can be replaced without delaying the class.