GE 48695 40 watt G25 Globe Bulb, Frosted Reveal GE incandescent lamps represents the state of the art of lamps for residential and commercial use, as well as special purpose lamps for decorative or display applications. In an incandescent lamp, light is generated by heating the filament to incandescence. The hotter the filament, the more efficient it is in converting electricity to light. However, when the filament operates hotter, its life is shortened so the design of each lamp is a balance between efficiency and life. This is why lamps of equal wattage may have different lumen ratings and different life ratings. Incandescent lamps of similar size are commonly available with different wattage ratings. The fixture wattage limit should not be exceeded.