9W Bulb refers to that bulb which contains tiny semiconductors wrapped in plastic to protect the elements and focus the light. This bulb uses much less energy than incandescent bulbs because diode light is much more efficient, power-wise, than filament light. This bulb is designed to resemble a traditional incandescent light bulb with visible filaments for aesthetic and light distribution purposes. 9W Bulb has a hassle factor and lasts a lot longer than a regular bulb. This is preferred more as it requires much less wattage than the CFL or other incandescent light bulbs. This bulb is very cost effective and can be easily purchased by our customers at nominal pricing.