Product Detail Closed-doublet projection head for sharper image and protection 2,500 lumens of light enhance your visuals even with the room lights on Specially engineered for a double lamp life of 130 hours average 10-by-10-inch staging area, built-in pen tray for convenient storage 10-foot power cord and tangle-free cord storage . The "3M Model 1730 Overhead Projector" is best product for you. We recommended 3M Model 1730 Overhead Projector