The brightness of a projector lamp fades over a period of time. Besides, lamp failure is inevitable and the sudden occurrence could spell trouble. If you are a traveling presenter, it is a good idea to always carry a spare lamp for such a possibility. The lamp provides bright and clear light, thus enhancing the performance of the projector.This Replacement Lamp has been specifically designed to be used with the ViewSonic PJ500 / PJ501 / PJ650 Projectors.